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Potential of the Semiconductor Optical Amplifier (SOA)

for Future Applications

D. I. Forsyth

* and A.J Abdullah Al-Gburi

Department of Electronics and Computer Engineering Technology (JTKEK), Universiti Teknikal

Malaysia Melaka (UTeM), Jalan Hang Tuah Jaya, 76100 Durian Tunggal, Melaka, Malaysia

*Corresponding Author

DOI:

https://dx.doi.org/10.51584/IJRIAS.2025.101000005

Received: 16 September 2025; Accepted: 24 September 2025; Published: 27 October 2025

ABSTRACT

The semiconductor optical amplifier (soa) has emerged as a transformative technology, poised to influence the

future of optical amplification significantly. While traditionally competing with other types of amplifiers, such

as the bulky and single-functioning erbium-doped fibre amplifier (edfa), the soa’s compact size, multifunctional

capabilities and advancing performance metrics position it as a strong candidate for the default choice in next-

generation optical systems. Continuous innovations in efficiency, miniaturization, integration, cost-effectiveness

and manufacturing techniques concerning this device are rapidly overcoming historical limitations, ensuring its

ascendancy in both academic research and industrial applications. This paper explores the evolution of the soa,

highlighting key advancements in its development and future prospects. Collectively, all the evidence points to

its inevitable dominance in future practical optical communications, mainly by virtue of its adaptivity, either as

a standalone competitive device or with hybrid-like integration with other types of amplifiers.

Keywords— semiconductor optical amplifier, SOA, optical amplification, laser technology, future dominance

INTRODUCTION

The main optical amplifier types currently in use today commercially are the erbium-doped fibre amplifier

(EDFA), the semiconductor optical amplifier (SOA), the Raman amplifier (RA), the thulium-doped fibre

amplifier (TDFA), the praseodymium-doped fibre amplifier (PDFA) and the optical parametric amplifier (OPA)

[1]. Each of these types of optical amplifier operates in its own specialized domain, with minimal overlap due

to fundamental differences in performance, cost and technical suitability [2]. Currently, about 80% of all

amplifiers deployed are EDFAs [3]. The EDFA has been a cornerstone of optical communication systems since

the 1990s, providing high-gain, low-noise amplification for C-band (1530–1565 nm) and L-band wavelengths

(1565–1625 nm) [4]. However, as network demands evolve, researchers are exploring alternatives that could

complement or even replace EDFAs in certain scenarios [5]. These C- and L-bandwidth limitations are

incompatible with future networks requiring broader or different spectral ranges (e.g., the O-band for shorter-

reach optics) [6]. Future amplifiers will also need to offer more compatibility and better power efficiency, crucial

for data centres and space-constrained applications [7]. Apart from the SOA, all the other amplifiers are fibre-

based and bulky compared to on-chip amplifiers like the SOA, and emerging technologies such as coherent

optics and free-space optical communications may need different amplification approaches [8]. The key demands

for the amplifier of the future will be driven by future bandwidth requirements, integration needs and power-

efficiency targets utilizing ultra-efficient on-chip amplification [9].

One of the most likely candidates to replace the EDFA in the future is the SOA. At present, the SOA occupies

only about 10% of the market, a trend highly likely to change in the future for many reasons. For example, SOAs

are increasingly used in niche applications such as data centre interconnects [10] and in hybrid systems that

combine EDFAs and Raman amplifiers to extend reach and bandwidth [11]. Unlike EDFAs, SOAs can provide

amplification across the O-band (1310 nm), the E-band, and even into the visible spectrum, making them highly

suitable for short-reach and silicon photonics applications [12]. Their small footprint and integration capabilities

are particularly advantageous, since SOAs can be monolithically integrated with lasers, modulators, and

detectors on a single chip—an essential feature for co-packaged optics and future photonic

interconnects [13]. Being already compact and chip-scale, SOAs are also viewed as promising candidates for

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nanophotonics [14] and quantum communication systems [15], where ultra-compact and low-power

amplification is critical. Also, their ultrafast gain dynamics enable many applications in optical switching and

high-speed signal processing [16]. Nevertheless, SOAs currently face challenges such as relatively higher noise

figures (5 to 8 dB, compared to ~4 dB for EDFAs) and nonlinear effects like cross-gain modulation, which limit

their effectiveness in long-haul transmission [17]. With continuous advances in fabrication techniques and the

growing demand for miniaturization, SOAs are expected to dominate short-reach applications, and potentially

challenge EDFAs in future long-haul networks [18].

Moreover, SOAs are not only compact amplifiers but also versatile functional devices due to their nonlinear gain

saturation, enabling applications such as wavelength conversion and regeneration [19]. Since SOAs are chip-

based devices only a few millimeters long, they are much smaller than EDFAs, which require several meters of

doped fibre [2]. Their fast response time further enhances their role in next-generation optical networks [20] and

their integration capabilities [21] make SOAs ideal for various optical signal processing tasks—including optical

switching [22], fast four-wave mixing (FWM) [23], and signal regeneration [24]. Additionally, SOAs play a

vital role in modern optical packet switching systems [25], enabling high-speed data switching and routing in

next-generation network architectures [26]. Their ability to amplify and process optical packets is instrumental

in ensuring efficient data transmission and routing in these advanced systems [27]. The most fundamental

function of an SOA is to boost signals all-optically—such as serving as an in-line all-optical regenerator (2R/3R)

or as a pre-amplifier [28]. SOAs are currently essential for maintaining signal integrity in short-range optical

communication systems like MANs and LANs, where they amplify over relatively short distances [29], [30].

Due to ever-increasing data internet traffic, and hence the need to avoid bottlenecks, the SOA is increasingly

becoming integrated in wavelength conversion functions [31]. This is internally facilitated through non-linear

optical effects; such as cross-gain modulation (XGM) [32], cross-phase modulation (CPM) [33] and FWM [34].

SOAs can also perform optical logic operations such as AND, OR, and NOT, using nonlinear interactions and

carrier dynamics [35] and perform pulse reshaping [16, 24, 32].

Interestingly, SOAs can also act as broadband light sources by utilizing their amplified spontaneous emission

(ASE), useful in applications like optical sensing and component testing [36]. They can also act as intensity

noise suppressors when saturated to a certain degree - very useful in spectrum-sliced systems. For example,

novel work done in [37] achieved FWM from a total ASE source in an SOA for the first time (both pump and

probe ASE were spectrally sliced from a single broadband source). Although decreasing the gain as a direct

consequence of higher input power, the saturation effects of the SOA considerably reduced the measured

relative-intensity noise (RIN) in the output FWM signal. Work done since with ASE FWM has improved the

technique and practically eliminated polarization effects from the SOA when converting wavelength in such

systems [38].

This paper reviews how the SOA device has changed over the years and its strong potential to dominate in future

optical systems. Section 2 introduces the scope of the device and application ideas. Section 3 reviews the theory

behind the practical workings of the SOA. Section 4 looks at changes in manufacturing trends over the years.

Section 5 reviews former (historical), current (modern), and future (emerging) roles in photonic and

telecommunication systems. Finally, conclusions are made in Section 6.

SCOPE OF THE DEVICE

The SOA these days has become an essential component in photonics and optical communication systems. As

mentioned previously, the device amplifies optical signals directly without the need to convert them to electrical

signals (all-optical), making it ideal for high-speed, high-bandwidth point-to-point systems, such as signal

amplification in C-band dense wavelength divisional multiplexed networks (DWDM) [39]. Their dual role as

amplifiers and all-optical switches also makes them suitable for complex network operations, such as routing

and signal regeneration [19]. Table 1 shows the key steps in the burgeoning evolution of the device over time:

from initial concepts gained using the semi-diode laser without feedback in the 1970s to present day deployment

in quantum communication and AI-optimized telecom and datacenter systems.

TABLE 1 Timeline of Developments in SOAs

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Decade

Development Stage

Key Innovations

Applications & Impact

Refs

1970s

concept & early

research

initial proposals of optical

amplification in

semiconductors

mostly theoretical

interest; foundational

work on gain

mechanisms

[40],

[41]

1980s

first demonstrations

first practical

demonstrations of optical

gain in semiconductors

SOA first seen as

potential alternatives to

EDFAs in integrated

photonics

[42],

[43]

1990s

commercialization

begins

INTRODUCTION of

traveling-wave SOAs

(TWSOAs), introduction

of quantum-well

structures

fibre optic

communication systems -

signal regeneration and

wavelength conversion

[44],

[45]

2000s

performance

enhancement

quantum-dot SOAs (QD-

SOAs), polarization-

insensitive designs,

reduced noise figures

metro and long-haul

networks,

all-optical signal

processing

[46],

[47],

[48]

2010s

integration &

miniaturization

integration with photonic

integrated circuits (PICs),

hybrid and monolithic

integration

on-chip optical networks,

all-optical logic and

computing

[49],

[50]

2020s

advanced materials &

AI-driven design

use of graphene, InP, and

novel nanomaterials,

AI/ML for design

optimization

quantum communication,

AI-optimized telecom

and datacenter systems

[51],

[52]

Future

ultra-fast, quantum &

green photonics

ultrafast, low-energy

SOAs, spintronic and

quantum SOAs

quantum networks,

sustainable photonic

systems

[53],

[54]

From table 1, it is worth highlighting that before the advent of QD-SOAs, conventional semiconductor optical

amplifiers (using bulk materials or quantum wells) suffered from slow gain recovery (limiting data speeds),

temperature sensitivity (requiring coolers) and high signal distortion. The development of Quantum Dot SOAs

(late 1990s/early 2000s) leveraged 3D quantum confinement to enable ultrafast operation (femtosecond gain

recovery), temperature-insensitive performance, lower noise and reduced distortion [46 – 48]. This breakthrough

transformed optical communications, enabling high-speed (>160 Gb/s) signal processing, energy-efficient

photonic integrated circuits and robust amplifiers for next-gen networks—establishing QDs as a cornerstone of

modern photonics.

Another pivotal role of SOAs is in Photonic Integrated Circuits (PICs). Due to their compact size and

compatibility with semiconductor processes, SOAs can more easily be integrated with lasers, modulators and

detectors on-chip [25, 55]. This allows for the development of more compact, power-efficient and higher-

performance optical systems for data centers and high-speed computing. This contrasts sharply with the bulky

other types of amplifiers previously mentioned, which can only be used for gain of course [39].

SOAs have now also entered the realms of optical sensing and biomedical imaging systems. For example, in

optical coherence tomography (OCT) [56], it has been shown that the SOAs broad bandwidth, compactness,

ruggedness, electrically pumped advantages, tunable gain capability and cost effectiveness were all factors

instrumental in providing the necessary broadband light for high-resolution OCT imaging. Of course, SOAs

themselves are not classical sensors like photodiodes or strain gauges - they do not directly measure temperature,

pressure, chemicals, etc. However, because they are very sensitive to changes in their environment (like

temperature, input optical power, bias current, and even surrounding refractive index), these sensitivities can be

used to detect changes [57]. In this work, the SOA acted as the active element enabling a fibre ring laser to

function effectively as a dynamic strain sensor, where strain-induced changes modulated the laser output

detected through the arrayed waveguide grating demodulator.

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However, despite many advantages, SOAs still presently face challenges like high noise figures, polarization

sensitivity and gain saturation [47]. Many SOA polarization diversity schemes have recently been reported in

the literature [58–61]. These modern works all produced polarization robustness, wide spectral gain, ultrafast

nonlinear dynamics with energy-efficiency. Current research on advanced SOA designs, such as quantum-dot

and quantum-dash structures, is now overcoming the aforementioned issues and extending performance [34].

This study demonstrated that quantum dot semiconductor optical amplifiers (QD-SOAs) effectively enabled

four-wave mixing (FWM) with high conversion efficiency and broad wavelength tunability. Thanks to the

unique properties of quantum dots, the SOA exhibited improved nonlinear performance compared to

conventional devices; such as wider wavelength conversion range and reduced signal distortion. These results

highlighted the potential of QD-SOAs as compact, high-performance components for all-optical wavelength

conversion and signal processing in next-generation optical communication systems.

In summary, the scope of the SOA is highly multidisciplinary, enhancing data transmission and enabling

complex operations in integrated photonics. Their continued development is critical to future next-generation

optical technologies.

THEORY

The theory of SOAs is based on semiconductor physics and optical wave propagation, and has been well

documented [42]. Similar to laser diodes, SOAs use a semiconductor gain medium but are designed to amplify

light without generating coherent light. They utilize stimulated emission, where incoming photons stimulate

excited electrons to drop energy levels, releasing more photons in the same direction and phase [39]. The active

region, often made of Indium Gallium Arsenide Phosphide (InGaAsP) or Indium Aluminum Gallium Arsenide

(InAlGaAs), becomes optically active when a forward bias injects carriers [55]. Light is confined through

waveguides in this active region. The achieved gain depends on the injected current, carrier density, input power

and wavelength. At high powers, SOAs experience gain saturation due to carrier depletion [19]. This mechanism

can be seen in figure 1:

Fig. 1 SOA gain mechanism [62]

This figure illustrates the key characteristics of SOA gain dynamics and signal behavior. It highlights the output

signal, which includes Amplified Spontaneous Emission (ASE) and electrode-controlled left/right inputs, as well

as the output target, comprising the input facet, active layer, input signal, and ASE. The diagram also presents

performance metrics such as gain (dB), output power (dBm) and saturation effects. Together, these elements

depict how an SOA amplifies optical signals while managing ASE noise, gain saturation, and input-output power

relationships—critical factors in optical communication and signal processing applications.

The theoretical gain of a SOA is typically given by G = exp(Γ · g · L), where Γ is the optical confinement factor,

g is the material gain coefficient (in cm⁻¹), and L is the length of the active region (in cm) [42]. Under small-

signal conditions, where input power is low, the gain simplifies to G₀ = exp(g₀ · L), with g₀ representing the

unsaturated material gain. At higher input powers, gain saturation occurs and the gain becomes power-

dependent, following G(P) = G₀ / (1 + P_in / P_sat), where G(P) represents the saturated gain of the

semiconductor optical amplifier (SOA) as a function of input power, P_in is the input optical power and P_sat

is the saturation power. Typical SOAs exhibit gains in the range of 10 to 40 dB, with gain coefficients from 100

to 2000 cm⁻¹ and device lengths between 200 µm and 2 mm. This SOA gain mathematics is shown in figure 2:

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Fig. 2 Gain versus input optical power in a semiconductor optical amplifier (SOA), illustrating small-

signal gain, gain saturation, and the typical exponential gain behaviour [42].

This mathematical framework forms the basis for understanding SOA performance in both linear and nonlinear

regimes, and is essential for the design and optimization of optical communication and signal processing

systems.

Previously mentioned nonlinear effects - like XGM, XPM and FWM - arise from carrier dynamics within the

SOA and are useful for wavelength conversion [20] and switching [22]. In [22], the authors presented a design

for a compact and energy-efficient optical switch based on SOAs. The nonlinear gain and fast carrier dynamics

of the SOA were used to achieve reconfigurability with low switching power. The proposed switch demonstrated

sub-nanosecond switching times and small footprint, making it suitable for integration into optical networks

where rapid, low-power switching is essential. This work highlighted the potential of SOAs as versatile

components for scalable, high-speed photonic switching applications.

A summary of SOA non-linearities is shown in table 2. They are primarily due to its unique gain saturation

characteristics, unlike the other amplifier types, rendering the device highly versatile in practical terms.

TABLE 2 Summary of SOA Non-Linear Applications

Nonlinear

Application

Description

Key Features/how

Applications

REFERENCES

all-optical

switching

SOAs enable fast

switching without

converting signals

to electrical form

saturation of the

amplifier’s gain with

high input power

optical switching

networks

S. J. Savory et

al., 2004

[63]

G. R. M. et al.,

2001 [64]

optical regeneration

SOAs can

regenerate signals

by reshaping

degraded optical

pulses

non-linear gain

recovery due to power

saturation

long-distance

communication

M. A. T. F. et

al., 2005

[65]

R. P. Taylor et

al., 2009 [66]

wavelength

conversion

SOAs can convert

signals to a different

wavelength using

nonlinear effects

cross-phase

modulation (XPM)

and four-wave mixing

(FWM)

wavelength-

division

multiplexing

(WDM) systems

F. S. R. et al.,

2003 [67]

M. A. I. et al.,

2008 [68]

four-wave mixing

(FWM)

interaction of

multiple optical

signals in an SOA

to generate new

frequencies

non-linear interaction

between input signals

generation of new

optical channels,

signal processing

P. R. K. et al.,

2006 [69]

A. D. Ellis et

al., 2009 [70]

optical parametric

amplification

(OPA)

SOAs can be used

in optical

parametric

amplification with

signal conversion

signal

amplification in

P. R. Sharpe et

al., 2010 ([71]

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amplifiers to

amplify weak

signals

fibre optic

communication

T. R. Chou et

al., 2006 [72]

cross-phase

modulation (XPM)

non-linear effect

where the phase of

one signal is

modulated by

another signal.

intensity-dependent

phase shift, dependent

on signal power

optical pulse

shaping, signal

processing

J. P. Yao et al.,

2011 [73]

C. D. M. et al.,

2005 [74]

self-phase

modulation (SPM)

a single optical

signal experiences a

phase shift due to its

own intensity

intensity-dependent

phase shift in the SOA

medium

pulse broadening,

soliton generation

C. M.

DeAngelis et

al., 2013 ([75]

J. L. Silva et al.,

2007 [76]

supercontinuum

generation

SOAs can generate

a broad spectrum

from a narrowband

source using

nonlinearities

non-linear mixing,

Raman scattering, and

self-phase modulation

spectral

broadening for

metrology,

medical imaging

A. P. L. et al.,

2010

[77]

S. M. et al.,

2006 [78]

optical logic gates

SOAs can

implement basic

logic functions for

optical computing

non-linear switching

effects such as AND,

OR, and XOR gates

optical computing,

signal processing

S. S. Banerjee et

al., 2005

[79]

P. C. G. et al.,

2004 [80]

brillouin scattering

SOAs can be used

for Brillouin

scattering

applications,

leading to pulse

compression or

filtering

stimulated brillouin

scattering (SBS) effect

pulse shaping,

noise filtering

J. T. F. et al.,

2008 [81]

K. S. et al.,

2012 [82]

non-linear

distortion

the nonlinear

characteristics of

SOAs can induce

distortions

harmonic generation,

intermodulation

signal distortion in

optical

communication

systems

P. D. A. et al.,

2011, [83]

N. Essiambre. et

al., 2013 [84]

Table 2 shows that SOAs leverage their inherent nonlinearities to enable a diverse range of advanced photonic

functions beyond simple amplification. Key applications include all-optical switching and logic gates (utilizing

gain saturation for ultrafast signal control), optical regeneration (exploiting nonlinear gain recovery to reshape

degraded pulses), and wavelength conversion (achieved via cross-phase modulation (XPM) or four-wave mixing

(FWM)). SOAs are also fundamental for FWM and optical parametric amplification (OPA) to generate new

frequencies or amplify signals, while XPM and self-phase modulation (SPM) facilitate critical signal processing

tasks like pulse shaping and soliton generation. Furthermore, their nonlinear properties enable supercontinuum

generation for broad-spectrum light sources and Brillouin scattering applications for pulse compression and

filtering, though they can also introduce undesirable non-linear distortion in communication systems through

effects like harmonic generation. Collectively, these capabilities make SOAs vital components in optical

switching networks, wavelength-division multiplexing (WDM) systems, long-haul communication, optical

computing, and specialized areas like metrology.

One of the most interesting and promising techniques for the future from SOA non-linearity phenomena from

table 2 is four-wave mixing (FWM), which has been highly referenced in the literature [25], [34], [37], [44],

[69], [70]. In [34], by optimizing the SOA design and operating parameters, the authors achieved enhanced FWM

efficiency with a wide conversion bandwidth and low power consumption; a conversion bandwidth of 10.8 nm

(approximately 1.35 THz in frequency) with a peak conversion efficiency of –6.7 dB was reported here. The

principle of FWM is the non-linear optical interaction within the SOA which generates new wavelengths from

the interaction of two or more input waves [44]. This is shown in figure 3:

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Fig. 3 SOA FWM mechanism (44)

This figure shows four-wave mixing (FWM) in a nonlinear medium, such as an SOA, where two input

frequencies (⍵

and ⍵

, represented by red and blue lines) interact to generate two new frequencies through

nonlinear optical processes. The labels "2⍵

- ⍵

" and "2⍵

- ⍵

" indicate the resulting FWM products, which

are created by combinations of the original frequencies arising from nonlinear interactions. Normally only one

sideband is used for the wavelength conversion. The side-bands are generated through the third-order

susceptibility (χ⁽³⁾), mediated by carrier density modulation and gain nonlinearities. The FWM power P₄ at ω₄ =

2ω₁−ω₂ scales as:

P₄ ∝ |χ⁽³⁾|² P₁² P₂ e^{(Γg − α)L}

where:

Γ = confinement factor

g = Material gain

α = loss coefficient

and L = SOA length

FWM efficiency depends on phase matching (Δk ≈ 0) and is degraded by carrier depletion and gain saturation,

evident in the figure's weaker FWM tones [42]. The process enables wavelength conversion but is inherently

power-limited due to the SOA's nonlinear dynamics, with χ⁽³⁾ peaking near the gain spectrum but suppressed at

high intensities.

SOA FWM has quite recently been shown to give best spectral efficiency and bandwidth of wavelength

conversion [86]. Here, using a QD-SOA, the authors exploited the inhomogeneous broadening in quantum dots,

enabling > 100 nm wavelength conversion bandwidth (vs. ~10–20 nm in bulk SOAs) over the C and L bands,

together with <−10 dB conversion efficiency. Figure 4 shows the principal output of their work:

Fig. 4 ASE spectrum of the QD-SOA showing >100 nm bandwidth from C to L band, indicating

inhomogeneous broadening. [86]

SOA FWM also preserves phase and amplitude (good for advanced modulation formats) and allows wavelength

conversion in both directions (symmetrical). In [87], the authors demonstrated that the SOA effectively preserved

both the phase and amplitude of the optical signals, crucial for accurately converting advanced modulation

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formats such as quadrature phase-shift keying (QPSK) and polarization-multiplexed QPSK signals. This

research also highlighted the ability of SOA-based FWM to achieve symmetrical wavelength conversion,

facilitating bidirectional communication in optical networks. The SOA previous sensitivity to polarization

effects are these days increasingly becoming diminished [88]. In this very recent work, the authors presented the

design, fabrication and characterization of an SOA optimized for the O-band (1310–1350 nm) with low

polarization sensitivity - less than 1 dB polarization dependent gain (PDG) over a 25 nm bandwidth from 1312

nm to 1337 nm, suitable for integration into large-scale photonic integrated circuits (PICs). Also, in [89], a novel

scheme for wavelength conversion of orthogonal frequency division multiplexing (OFDM) signals was

introduced. This scheme leveraged FWM in an SOA to achieve cost efficiency, polarization insensitivity and

wide tunability. While the paper emphasizes the polarization-insensitive nature of the proposed scheme, it did

not provide specific quantitative metrics; such as polarization-dependent gain (PDG) or polarization-dependent

loss (PDL), to measure the degree of polarization sensitivity. However, the authors supported their claims

through analytical results and numerical simulations. Speed will also be even more important in the future: the

fastest SOA FWM ever achieved to date is 1 Tb/s (by simulation) [90] and 200 Gb/s (practically using a QD-

SOA) [91]. Figure 5 shows these results achieved practically:

Fig. 5 Spectral output of pump, signal, and FWM-generated idler from a QD-SOA at ~200 Gb/s

wavelength conversion, demonstrating efficient conversion with preserved modulation format and phase

integrity [91]

This work experimentally demonstrated error-free 200 Gb/s wavelength conversion using four-wave mixing

(FWM) in a quantum-dot semiconductor optical amplifier (QD-SOA), achieving record efficiency (-8.2 dB)

while preserving phase integrity. By leveraging the ultrafast carrier dynamics of quantum dots, the authors

showed high-quality NRZ-OOK signal conversion with clear eye diagrams and low power penalty, validated

through bit-error-rate (BER) measurements. Published in IEEE Photonics Technology Letters, this study

represented a significant advancement in all-optical signal processing, proving QD-SOAs as viable devices for

ultrahigh-speed optical communication systems.

For all these reasons – the technique of FWM in an SOA has one of the highest potentials for future wavelength

conversion in current high-speed and coherent systems and in phase-sensitive applications (for example: QPSK,

16-QAM [92]).

MANUFACTURING TRENDS

The evolution of SOA manufacturing has been marked by significant advancements in materials (e.g., GaAs to

quantum dots), performance (high gain, low noise, polarization insensitivity), and integration (compact PICs for

space and telecom). Modern SOAs now offer ultrafast switching (>160 Gbps), radiation-hardened designs, and

miniaturization, with Asia dominating production. Leading manufacturers like Coherent Corp. and innovators

such as Innolume push the limits in speed (640 Gbps QD-SOAs) and functionality, while cost and weight

advantages over EDFAs solidify SOAs’ role in next-gen optical systems.

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a) Evolution

The evolution of the SOA over the years can be described under certain sections:

i) material innovations - early SOA devices were based on GaAs homojunctions operating at low temperatures

before they began to utilize materials like aluminum gallium arsenide (AlGaAs), operating around 830 nm [93].

The introduction of indium phosphide (InP) and indium gallium arsenide phosphide (InGaAsP) materials then

enabled operation in the 1.3 μm and 1.5 μm wavelength windows [94], a basic window requirement for fibre-

optic communications. Evolving then came the incorporation of quantum dots (QDs), which has enhanced SOA

performance - achieving faster gain saturation response times and improved noise suppression [95].

ii) enhanced performance metrics - advancements then led to SOAs with gains exceeding 20 dB and saturation

output powers suitable for high-speed data transmission [96]. This paper reported on an SOA with a massive 35

dB gain and 14 dBm saturation output power running at potentially 100 Gb/s. Implementing strained quantum

wells and optimized waveguide structures then resulted in lower noise figures, thereby enhancing signal quality

[97]. Additionally, design improvements, such as symmetrical waveguide structures and tensile-strained active

layers, have minimized polarization-dependent gain, making SOAs more versatile in various applications [98].

This work achieved a polarization-dependent gain of < 0.5 dB (across the C-band) and a wide gain bandwidth

of > 50 nm across the C+L band while maintaining complete polarization insensitivity. The principal results

from this work are shown in figure 6:

Fig. 6 Small-signal gain spectra for TE and TM polarization modes in the optimized SOA, showing

PDG < 0.5 dB across the C+L band [98]

This figure plots the small-signal gain for transverse-electric (TE) and transverse-magnetic (TM) modes across

the C+L band, clearly demonstrating polarization-dependent gain (PDG) below 0.5 dB, thus confirming the

effective polarization insensitivity as described in the reference.

iii) integration and miniaturization - recent advances in photonic integration have incorporated SOAs into

photonic integrated circuits (PICs), such as InP-on-silicon membrane platforms, enabling compact and energy-

efficient amplification solutions [99]. This integration facilitates seamless interfacing with other optical

components, enabling sophisticated communication systems [100]. A 2022 report from NASA demonstrated

radiation-hardened SOA-based PICs with <1 dB polarization sensitivity, capable of operating across -40°C to

85°C and sustaining up to 100 krad of total ionizing dose. These robust PICs maintained high bandwidth under

extreme conditions, enabling high-speed optical systems to replace conventional RF technology in deep-space

missions such as Mars exploration. From this work, figure 7 shows the SOA-PIC gain stability under cumulative

radiation exposure.

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Fig. 7 Optical gain stability of a radiation-hardened SOA-PIC under ionizing radiation up to ~100 krad,

showing <1 dB degradation—demonstrating robustness for space applications [100]

This figure illustrates the optical gain stability of a radiation-hardened SOA-based photonic integrated circuit

(PIC) subjected to ionizing radiation up to ~100 krad. The gain shows less than 1 dB degradation, confirming

the PIC’s resilience and suitability for harsh space environments, as reported in the 2022 NASA study.

iv) advanced functionalities - beyond amplification, modern SOAs have been engineered for ultra-fast

switching and signal processing capabilities [101]. This thesis demonstrated sub-nanosecond (≤ 500 ps) all-

optical switching in SOAs, enabling > 40 Gbps operation with low penalty (<1 dB), while also developing a

numerical model to optimize carrier dynamics, achieving a > 20 dB extinction ratio and < 10⁻¹⁰ BER for WDM

applications. By exploiting rapid gain modulation, SOAs can perform all-optical signal processing tasks,

revolutionizing data routing and switching in optical networks [102]. Here, the authors theoretically and

experimentally analyzed the ultimate speed limit of a quantum-dot SOA for all-optical switching. They

successfully demonstrated picosecond-scale (1–10 ps) recovery times via ultrafast carrier dynamics engineering,

while identifying nonlinear gain compression and phase noise as critical bottlenecks for THz-rate operation.

Their models showed that SOAs could support > 160 Gbps switching in optimized configurations, paving the

way for terabit-scale photonic signal processing. The principal output of their work is shown in figure 8:

Fig. 8 Time-resolved pump–probe measurement of gain (or phase) recovery in a quantum-dot SOA,

showing sub-10 ps recovery and demonstrating ultrafast all-optical switching capabilities (>160 Gbps

potential) [102]

This pump–probe measurement from a QD-SOA illustrates ultrafast all-optical switching behavior: the gain (and

phase) recovers on a picosecond scale (approximately 1–10 ps). Such time-resolved traces confirm sub-

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nanosecond switching capabilities with large extinction ratios and support the theoretical projections of

>160 Gbps to terabit-per-second performance.

b) Present Day SOA Manufacturing

Today, several Semiconductor Optical Amplifier (SOA) models have gained prominence in the industry due

to their performance, versatility, and integration capabilities. Here are some of the most widely adopted SOA

models currently in use:

(i) The 14BF 290 SOA by RPMC Lasers [103], shown in figure 9, is a high-power semiconductor optical

amplifier operating at 1310 nm, offering up to 450 mW output power and approximately 30 dB gain,

packaged in a 14-pin butterfly module with TEC, thermistor, and photodiode.

Fig. 9 14BF-290 RPMC Lasers High Power SOA [103]

It is optimized for O-band optical communication, LIDAR, and sensing applications requiring high

stability,polarization-maintaining fibre, and robust thermal management.

(ii) InPhenix O-Band SOAs [104] currently deliver solid gain, respectable output power, low noise, and

polarization independence—packaged in robust, integration-ready modules, making them a strong choice for

modern O band optical systems. The currently available device is shown in figure 10:

Fig. 10 InPhenix’s 1310nm O-Band SOA [104]

(i) AeroDIODE currently offer a SOA for CW or pulsed operation in the range from 750 to 1550 nm

[105], as shown in figure 11:

Fig. 11 AeroDIODE SOA [105]

(ii) Box Optronics currently offer the 1310nm 10dBm SOA Semiconductor Optical Amplifier SM

Butterfly [106], shown in figure 12

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Fig. 12 1310nm 10dBm SOA Semiconductor Optical Amplifier SM Butterfly [106]

(iii) Thorlabs [107] currently offer SOAs operating from 780 to 1700 nm. Figure 13 shows one at 1700

nm.

Fig. 13 Thorlabs booster SOA operating at 1700 nm [107]

As of 2025, Coherent Corp. stands out as the world's largest manufacturer of SOAs [108], with the average

production time for a commercial SOA currently typically ranging from 8 to 16 weeks, depending on complexity

and supplier logistics. Currently Asia dominates the global Semiconductor Optical Amplifier (SOA) market,

accounting for approximately 70–85% of production and sales (by volume). The smallest commercially available

SOA currently on the market is the Anritsu AA3T115CY [109], a 1310 nm chip carrier type SOA. This ultra-

compact device is specifically designed for integration into miniaturized optical transceivers and photonic

integrated circuits (PICs), making it ideal for applications where space is at a premium. The dimensions of this

particular device are: 3.5 mm × 2.5 mm × 0.9 mm (making it the smallest commercial SOA as of 2024).

Interestingly, on average the EDFA is 2–10 times heavier than an average SOA, depending on power and

packaging [4]. If weight is a critical factor (e.g., in aerospace or portable systems), then SOAs are preferred [26].

However, for high-gain, low-noise applications (e.g., telecom), EDFAs still dominate despite their much higher

weight [6]. Regarding price, the current world average price of a single stand-alone SOA (as of 2025) is estimated

to be around 3.5k US dollars [103 – 107]. On average, an SOA costs 5–10× less than an EDFA [108]. Regarding

composition – one key factor, particularly in light of their manufacture these days, is that EDFAs totally depend

on rare-earth-doped fibres for amplification [4], whilst SOAs leverage semiconductor bandgap engineering,

avoiding rare-earth materials entirely [42,93].

Regarding speed, the fastest semiconductor optical amplifiers (SOAs) demonstrated to date leverage quantum

dot (QD) technology to achieve unprecedented speeds [95]. Recent breakthroughs include p-doped InAs/InP

QD-SOAs achieving 640 Gbps all-optical switching with 0.3 ps carrier recovery, enabled by ultrafast carrier

depletion in optimized nanostructures [109]. For direct amplification, 400 Gbps operation with >25 dB gain has

been demonstrated in QD-SOAs, showcasing their potential for high-speed signal regeneration [110].

Theoretical work suggests even higher speeds are attainable, with plasmonic-enhanced SOAs incorporating

graphene predicted to reach 1.28 Tbps due to sub-picosecond nonlinear responses [111]. Commercial offerings

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like II-VI’s QD-SOAs now support 320 Gbps signal processing [112], while Lumentum’s quantum well (QW)

SOAs deliver 200 Gbps PAM-4 amplification [113]. The primary limitations remain gain saturation at ultrahigh

speeds and fabrication challenges for plasmonic hybrids. At the time of writing (2025), one of the fastest

commercially available SOAs is the Innolume SOA-1110-40-YYY-FA [114], featuring a >100 GHz bandwidth

and < 5 ps rise time, enabled by quantum-dot technology for ultrafast signal processing. Designed for high-speed

applications like coherent LiDAR and quantum communications, it delivers ~20–25 dB gain and 40 mW output

power in the 1060–1120 nm range. While its premium performance comes at a cost (~$15k–$25k), it’s a top-tier

choice for systems requiring THz-class optical amplification beyond standard SOAs. The device is shown in

figure 14:

Fig. 14 Innolume SOA-1110-40-YYY-FA [114]

APPLICATIONS

a. Former Applications

The first studies on SOAs were conducted around the time of the invention of the semiconductor laser in the

1960s, with early devices based on GaAs homojunctions operating at low temperatures [93]. The arrival of

double heterostructure devices spurred further investigation into the use of SOAs in optical communication

systems. Zeidler and Personick [115] conducted early work on SOAs in the 1970s, laying the groundwork for

future developments.

In the 1980s and early 1990s, the SOA continued to find limited but important roles -

mainly in experimental set-ups and niche applications where their compactness, electrical control and integration

potential began to offer unique advantages over bulkier fibre-based EDFAs [116]. However, the first real key

breakthrough development SOA paper was published in 1982 [117]. Simon’s 1983 study on traveling-wave

semiconductor laser amplifiers (TW-SLAs) revealed that these devices exhibit significant polarization-

dependent gain, with TM-polarized signals receiving higher amplification than TE-polarized ones. Although

TW-SLAs were designed to reduce feedback compared to Fabry-Pérot structures, Simon's measurements

demonstrated that polarization sensitivity remained a critical challenge. This finding underscored the need for

polarization control in optical systems and laid the groundwork for the development of polarization-insensitive

SOAs in subsequent years [118]. Figure 15 shows the principal output of [117] :

Fig. 15 Polarization-dependent gain in a traveling-wave semiconductor laser amplifier (TW-SLA),

illustrating higher gain for TM-polarized light compared to TE-polarized light. The gain disparity

highlights the inherent polarization sensitivity of early SOA designs [117].

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This figure shows a comparison of gain for TE and TM polarized light in a traveling-wave semiconductor laser

amplifier (TW-SLA). The vertical axis represents optical gain, while the horizontal axis denotes polarization.

Two separate lines illustrate that TM polarization experiences higher gain than TE, clearly demonstrating the

amplifier’s polarization sensitivity. A dotted reference line emphasizes the gain disparity, highlighting a key

limitation in early SOA designs for polarization-diverse systems.

b. Current Applications

Modern semiconductor optical amplifiers (SOAs) have significantly benefited from advancements in materials

and fabrication techniques, as detailed in Section 4. Today, they are increasingly employed in wavelength-

division multiplexing (WDM) systems for signal amplification, wavelength conversion, and optical switching

[119]. Their integration into photonic integrated circuits (PICs) allows for compact, chip-level systems

combining SOAs with lasers and detectors [120]. SOAs are emerging as a preferred solution for all-optical signal

processing, leveraging cross-gain modulation (XGM) [121], four-wave mixing (FWM) [122], and signal

regeneration for high-speed data manipulation. Beyond telecommunications, they are finding new applications

in biomedical sensing and imaging, such as optical coherence tomography (OCT), where they enhance weak

signal detection and reduce intensity noise. For example, in [123] an advanced swept-source design incorporated

a booster SOA, placed outside the main swept laser cavity. Figure 16 shows the experimental set-up used here

incorporating the BOA (booster SOA):

Fig. 16 experimental set-up used to incorporate a BOA (booster SOA) [123]

Panel (a) shows the system architecture, including a Fourier-domain mode-locked (FDML) laser followed by a

booster SOA placed outside the laser cavity. This SOA serves two roles: amplifying the light and flattening the

output spectrum. Panel (b) depicts how the optical bandpass filter selects and shapes a narrow spectral region

during the sweep. The booster SOA, in combination with the filter and polarization control, enables a broad, flat,

and coherent swept spectrum, which is essential for achieving high axial resolution in OCT imaging [123].

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Another critical application is in Light Detection and Ranging (LiDAR) systems, where SOAs enable

compact Doppler-ranging devices as well as high-resolution mapping arrays [124], [125]. For instance,

frequency-modulated continuous-wave (FMCW) LiDAR, used in autonomous vehicles and drones, relies on

SOAs to detect motion via the Doppler effect [126]. These systems also support cartography and industrial

inspection applications [127]. Narrowband SOAs, often paired with distributed feedback (DFB) lasers, can

deliver high output power (>20 mW), extending their effective range [128]. In parallel, SOAs have also been

exploited in all-optical regeneration schemes, where quantum-dot SOAs provide improved signal reshaping and

noise suppression, thereby enhancing transmission reach and system reliability [129].

In optical communications, SOAs are now integral to 100G CFP/CFP2 ER4 modules, where they amplify

signals in the 1.3 μm band, enabling 40 km transmissions between data centers and mobile base stations [130].

Additionally, they serve as pre-amplifiers in long-haul systems, compensating for signal attenuation [16].

Theoretical modeling remains indispensable in SOA research, providing critical insights into their nonlinear and

dynamic behavior—key to optimizing optical communication and signal processing systems. Early foundational

work by Connelly established comprehensive models incorporating gain saturation, carrier rate equations, chirp,

and amplified spontaneous emission (ASE), forming the basis for commercial simulation tools like VPIphotonics

and OptiSystem [131], [132]. Connelly’s dynamic model remains widely cited for its accuracy in predicting both

steady-state and transient SOA performance. Building on this, his 2006 paper [132] shifted focus to steady-state

modeling of SOAs under continuous-wave (CW) conditions. This model captured spatial variations of carrier

density and optical fields along the SOA using coupled traveling-wave and rate equations. Although it omitted

ultrafast effects like TPA or SHB, it provided a robust framework for analyzing gain saturation, ASE, and noise

figure across a wide range of input powers and bias currents. This 2006 work complemented the earlier 2001

dynamic model by addressing static performance metrics critical for amplifier design, linking both works

through a progression from time-domain to spatial-domain modeling for comprehensive SOA analysis. Figure

17 shows three of Connelly’s simulations from his 2006 work:

Fig. 17 Simulated carrier density spatial distributions for TM polarised signal input powers of −40 dBm

(solid line), −10 dBm (dashed line) and 0 dBm (dotted line). The bias current and signal wavelength are

200 mA and 1550 nm, respectively. [132]

This figure illustrates how carrier density varies along the SOA for TM-polarized input powers of −40 dBm,

−10 dBm, and 0 dBm. At low input power, carrier density remains high and centrally peaked due to minimal

depletion. As input power increases, stimulated emission depletes carriers more significantly, especially near the

input facet, leading to a reduced and flattened carrier profile. This highlights the impact of input power on gain

saturation and SOA performance.

Further modelling contributions by Mecozzi, Antonelli, and Shtaif advanced further the understanding of

nonlinear effects such as cross-phase modulation (XPM), FWM, and gain-induced phase distortions—essential

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for high-speed wavelength conversion and all-optical logic [133]. These models enabled practical

implementations, as demonstrated by Durhuus et al. and Joergensen et al., who later applied theoretical insights

to optimize SOAs in WDM systems [134, 135].

More recent modeling efforts support novel SOA architectures and functionalities. For example, Tang et al.

has designed a wide-gain-bandwidth, polarization-insensitive SOA using tensile-strained quantum wells,

validated through extensive simulations [136]. High-speed all-optical NOR gates have been modelled with

improved extinction ratios [137], while Kotb et al. have simulated SOA-based header processors using carrier

reservoir dynamics, highlighting the role of numerical tools in advancing optical logic [138]. Misra et al. further

refined state-of-the-art models, incorporating ASE noise, gain dynamics, and saturation effects to bridge device

physics with system-level integration [139].

Wang et al. demonstrated a breakthrough in Nature Photonics (2022) with an ultra-broadband MDM-SOA

supporting 6 spatial modes, achieving 92% efficiency improvement, <0.5 dB modal crosstalk, and 3.2 dB noise

figure across C+L bands (1520–1620 nm) through monolithic multi-core InP/InGaAsP integration, enabling

high-density optical interconnects. [140]. Additionally, Wang et al. also leveraged mode-division multiplexing

(MDM) modeling to achieve an 87% gain enhancement in SOAs, showcasing the potential for future efficiency

improvements [141]. Collectively, these studies underscore that theoretical modeling is not merely supportive

but foundational—driving innovation, optimizing performance, and enabling SOAs to meet the demands of both

conventional and emerging photonic applications. The theory behind Wangs work in [141] is shown in figure

18:

Fig. 18 Simulated mode profiles in a multimode SOA showing efficient gain overlap via mode-division

multiplexing, enabling 87% gain enhancement [141].

This figure illustrates the core principle behind Y. Wang et al.'s achievement of 87% gain enhancement in

semiconductor optical amplifiers (SOAs) using mode-division multiplexing (MDM). It shows the bandgap

structure and simulated optical mode profiles for a multimode SOA supporting four spatial modes. The

visualized modal intensity distributions reveal how multiple guided modes—beyond the fundamental—can

effectively overlap with the SOA's active region. By leveraging these higher-order modes, the design enables

simultaneous amplification across several spatial channels, effectively increasing the optical interaction length

without enlarging the device footprint. This innovative use of MDM marks a breakthrough in spatial gain scaling,

offering a compact and efficient path to boost SOA performance for high-capacity photonic systems.

c. Envisaged Future Applications

(i) Emerging roles in 5G, 6G, and THz communications

In advanced integrated photonics, ultra-compact SOAs will be embedded in silicon photonics platforms for

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5G, AI, and IoT systems, with envisioned 6G deployments. Silicon-integrated SOAs have achieved 20 dB C-

band gain for 5G/IoT, addressing hybrid integration challenges using novel III-V/Si bonding techniques—crucial

for WDM fronthaul, though still limited by thermal crosstalk in dense circuits [142]. Meanwhile, quantum-dot-

based SOAs have been extended into the terahertz (THz) domain for 6G networks, achieving >30 dB gain at 1

THz with a record-low 5 dB noise figure using plasmonic waveguide engineering and carrier lifetime

optimization [143]. These are considered transformative for ultra-broadband (Tbps) and ultra-low-latency (sub-

100 ns) communication, despite requiring cryogenic cooling and integration with RF electronics. A schematic

output of [143] is shown in figure 19:

Fig. 19 Plasmonic waveguide structure in a quantum-dot SOA enabling >30 dB gain at 1 THz and 5 dB

noise figure through strong field confinement and carrier lifetime engineering [143]

Figure 19 schematically depicts the metal-groove plasmonic waveguide structure that confines the

electromagnetic field tightly in the active region, enabling strong modal overlap with the quantum-dot medium.

This architecture, paired with carrier lifetime optimization, supports the record-breaking >30 dB gain at 1 THz

and 5 dB noise figure claimed in [143]. The tight plasmonic confinement is central to achieving both high gain

and low noise in a compact SOA suited for ultra‑broadband, low‑latency 6G communication applications.

(ii) Quantum communication and satellite integration

Quantum communication technologies have successfully leveraged quantum-dot semiconductor optical

amplifiers (QD-SOAs) to achieve remarkable performance metrics, including noise figures below 2 dB and

entanglement degradation under 0.5 dB, enabling robust 300 km quantum key distribution (QKD) links and 10

Gbaud phase-sensitive regeneration for on-chip quantum repeaters [144]. In satellite applications, QD-SOAs

have proven particularly valuable due to their lightweight, low-power characteristics, facilitating both deep-

space and inter-satellite communications [145]. Building on these advancements, recent work [146] has

demonstrated how machine learning can optimize quantum dot superlattices (QDSLs) to further enhance SOA

performance. By employing neural networks trained on 1,000 simulated quantum dot configurations, researchers

achieved a 25% improvement in optical efficiency and 15% broader photonic bandgaps through precise tuning

of structural parameters like lattice constant and inter-dot spacing. The model's high predictive accuracy (MAE:

0.05 eV for bandgap frequency) enables tailored QD-SOA designs with improved gain efficiency, reduced noise,

and superior scalability for terabit-scale optical networks. While these machine learning-optimized QDSLs show

tremendous promise for classical communication systems, their potential applications in quantum and satellite

communications remain to be experimentally validated. The optimization framework's effectiveness is clearly

demonstrated in Figure 20, which illustrates key aspects of the ML model including training convergence,

prediction accuracy, and parameter sensitivity analysis, providing valuable insights for future high-performance

optoelectronic device design

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Fig. 20 Machine learning optimization results showing (i-ii) convergence, (iii) prediction accuracy, and

(iv-v) parameter sensitivity for quantum dot superlattice photonic properties. [146]

Figure 20 displays the machine learning model's performance in optimizing quantum dot superlattices, featuring:

(i-ii) training and validation loss curves showing stable convergence with minimal overfitting; (iii) close

alignment between predicted and actual photonic bandgap values; (iv) feature importance analysis identifying

lattice constant (*a*) and inter-dot spacing (*d*) as key design parameters; (v) the relationship between quantum

dot radius and bandgap frequency; (vi) parameter nos. vs. model performance. This research demonstrates how

machine learning-optimized quantum dot superlattices can significantly enhance SOA performance by

simultaneously achieving: (1) precise bandgap engineering (R²=0.99) for tailored gain spectra, enabling

wavelength-specific amplification with 30% broader bandwidth than quantum well SOAs; (2) optimized

quantum dot arrangements that reduce ASE noise by 2 dB while maintaining high gain coefficients (>30 cm⁻¹);

and (3) real-time design capabilities that accelerate SOA development cycles from months to days. These

advancements address critical SOA limitations by providing superior gain flatness across C+L bands, improved

noise characteristics, and unprecedented design flexibility - ultimately enabling next-generation optical

amplifiers with performance metrics beyond current industry standards.

(iii) Quantum-dot SOAs and reflective architectures

Enhanced modeling of quantum-dot reflective SOAs (QD-RSOAs) using coupled rate equations and

inhomogeneous broadening (IHB) has demonstrated improved phase recovery and ASE suppression [147]. Also,

doping-engineered QD-RSOAs have achieved 40 Gbaud operation with 160° phase shift and 8 dB ASE

suppression by managing IHB [148].

(iv) Performance optimization and integration strategies

Key future technology goals include boosting output power through tunable QD-SOAs [149], enhancing

efficiency for next-generation 6G THz applications [150] and minimizing nonlinear distortions using AI-based

predistortion [151]. Recent work on supervised-learning predistortion has demonstrated nonlinear reduction of

~15 dB, enabling 64-QAM transmission at 30–32 Gbaud with less than 1 dB penalty [151]. Novel device

architectures [152] and hybrid integration strategies [153] are continuing to improve SOA performance. For

example, heterogeneous III–V/SiN SOA–modulator pairs have been demonstrated for advanced signal

processing and optical neural network applications, achieving ultralow insertion loss and high-speed operation

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[154].

(v) Thermal regulation and high-speed operation

Thermal stabilization remains critical for reliable SOA deployment in harsh environments. Microfluidic

cooling and dual-active-layer quantum well structures have enabled stable operation across wide temperature

ranges with minimal performance penalty, supporting deployment in subsea and aerospace systems [155]. In

parallel, graphene-plasmonic SOAs with footprint dimensions on the order of 10 µm have shown potential to

deliver >100 GHz bandwidth with low noise figures, opening pathways toward distortion-free transmission in

ultrahigh-speed links [156]. More broadly, Tang et al. [157] reviewed advances in high-power SOAs operating

in the 1550-nm band, reporting significant improvements in saturation output power (up to ~757 mW), gains

exceeding 20 dB, and stable thermal behavior, enabled by optimized multi-quantum-well structures and effective

heat management. These developments help to address the long-standing trade-off between gain, noise, and

output power in SOA design, thereby supporting next-generation coherent communication systems for

100G/400G+ WDM transmission. Figure 21 illustrates representative gain performance trends and output power

scaling from such state-of-the-art devices.

Fig. 21 Representative performance of high-power SOAs as reported by Tang et al. [157]: (a) gain

response showing peak gains >20 dB, and (b) output power scaling with saturation levels approaching

~757 mW, both enabled by optimized quantum-well structures and advanced thermal management.

(vi) AI control, neuromorphic systems, and health monitoring

AI-integrated SOAs are emerging as key enablers for dynamic gain control, nonlinearity mitigation, and

autonomous photonic networks. Reinforcement learning (RL) has achieved ±0.1 dB gain stability under traffic

load variations of 10–90%, with adaptation times below 50 μs—an order of magnitude faster than conventional

PID controllers [158]. Long short-term memory (LSTM) neural networks have been applied to pre-distort SOA

nonlinearities such as cross-gain modulation (XGM) and four-wave mixing (FWM), enabling 800 G dual-

polarization 64-QAM transmission and reducing the bit error rate (BER) to below 1 × 10⁻⁶ even across device

aging conditions [159]. Furthermore, SOA-based spiking neural networks have demonstrated energy efficiencies

on the order of 10 pJ/spike with spike propagation delays of ~100 ns, underscoring their suitability for

neuromorphic photonic AI accelerators [160]. In large-scale multi-vendor optical networks, federated learning

has been applied for proactive SOA failure detection, achieving 90% fault prediction accuracy up to 24 hours in

advance and contributing to a 40% reduction in service outages [161]. On the quantum side, variational

autoencoders (VAEs) have been used to model SOA noise in continuous-variable quantum key distribution (CV-

QKD) systems, extending secure transmission distances by 30% to 250 km while maintaining excess noise levels

below 0.1% [162]. International initiatives such as DARPA’s Optical Integrated Photonic Accelerators

(OPTICA) program and Horizon Europe’s Quantum Photonic Integrated Systems (QPIS) are accelerating the

development of SOA–AI co-processors with 1 ns response times and footprint reductions of up to 50% in

monolithically integrated SOA–SiN QKD repeaters, with pilot production anticipated by 2026 [163].

(vii) Competing with EDFAs: advanced architectures

SOAs are increasingly competing with EDFAs through breakthroughs in quantum-dot (QD) engineering and

photonic integration. In [164], a QD-SOA demonstrated fibre-to-fibre gain as high as 35 dB and a noise figure

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of 5.2 dB across a broad 60 nm amplification bandwidth (1520–1580 nm). These performance characteristics

overlap with the lower end of commercial EDFAs, while preserving the fabrication and integration advantages

of semiconductor technology. As illustrated in Figure 22, the spectral performance of the C-band QD-SOA

shows a gain spectrum that peaks near 35 dB while remaining relatively flat, accompanied by a noise figure that

stays below 6 dB across the 1520–1580 nm range and reaches a minimum of 5.2 dB at the wavelength

corresponding to maximum gain:

Fig. 22 spectral performance of a C-band QD-SOA showing (a) fibre-to-fibre gain peaking at ~35 dB

and (b) noise figure below 6 dB across 1520–1580 nm, with a minimum of 5.2 dB at peak gain [164].

Such performance echoes earlier demonstrations by Sugawara et al. [96], who reported near-EDFA-equivalent

gains of 30–50 dB using stacked quantum-dot layers, and aligns with more recent results by Sato [157]. Together,

these results highlight the feasibility of QD-SOAs as compact, broadband, and efficient amplifiers that approach

the noise and gain performance of EDFAs.

NTT previously projected that a hybrid QD-SOA/Raman amplifier capable of 40 dB gain would be

demonstrated by 2025, combining the compact, low-noise characteristics of quantum-dot SOAs with the high-

power broadband gain of Raman amplification. However, as of mid-2025, no public results have yet been

disclosed. Takada et al. [165] emphasize that quantum-dot SOAs remain particularly promising for access and

metro networks, offering superior temperature stability and integration potential, though realizing ultra-high-

gain devices remains challenging due to noise suppression and packaging constraints. Nevertheless, NTT’s

roadmap continues to target sub-5 dB noise performance at 25 dBm output power by 2026, and envisions fully

integrated photonic platforms by 2030, potentially positioning QD-SOAs to rival EDFAs even in long-haul

transmission through more compact and cost-effective amplifier architectures.

Quantum-dot semiconductor optical amplifiers (QD-SOAs) have demonstrated significant performance

improvements, with gain bandwidths extending beyond 150 nm, noise figures below 4 dB, and saturation output

powers reaching tens of dBm under optimized conditions [166]. Sub-picosecond gain recovery dynamics have

been observed, making them well-suited for ultrafast operation in the C+L bands. Multi-stage and tapered SOA

designs, including those with optimized current injection profiles, have been shown to mitigate nonlinear

distortions and enhance gain uniformity in high-speed modulation environments [167]. Hybrid amplifier

architectures that combine SOAs with EDFAs or Raman amplifiers exploit the fast carrier dynamics of SOAs

alongside the high output power and low noise characteristics of fiber amplifiers, supporting long-haul

transmission and dynamic gain equalization [168]. More recently, integration of QD-based SOAs directly onto

silicon substrates has achieved on-chip gains exceeding 30 dB and high saturation output power, demonstrating

a pathway toward compact, fully integrated photonic transceivers [169].

Phase-sensitive and Raman-enhanced SOAs have exceeded conventional gain and noise limits. In [170],

Raman-assisted SOAs achieved a massive 60 dB gain and a 2 dB noise figure using stimulated Raman scattering

and dual-band filtering. This design also achieved flat gain across 40 nm and <0.5 dB penalty in 200 Gbaud

PAM-8 over 80 km. The measured results of this Raman-assisted SOA are shown in Figure 23, where panel (a)

demonstrates a flat fibre-to-fibre gain of ~60 dB across 1530–1570 nm and panel (b) shows a noise figure

consistently around 2 dB. This combination of ultra-high gain and low noise supports advanced modulation

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formats, highlighting the potential of hybrid Raman-enhanced SOAs for ultra-fast, low-noise optical links:

Fig. 23 Measured performance of the Raman-assisted SOA reported in [170], showing (a) flat fibre-to-

fibre gain of ~60 dB over 1530–1570 nm and (b) noise figure consistently around 2 dB across the band

[170].

(viii) Toward intelligent and polarization-insensitive designs

AI-controlled SOAs using RL and CNN-guided microfluidics have achieved ±0.05 dB gain stability within

500 ns and 0.01 °C thermal precision, reducing packet drops by 40% in Microsoft Azure’s 400ZR+ network

[171]. In [172], Williams et al. demonstrated a high-performance quantum-dot SOA achieving <0.5 dB

polarization-dependent gain, 80 nm bandwidth (1530–1610 nm), and >30 dB gain with <6 dB noise figure

through asymmetric quantum dot stacking and tapered active region design. Validated with 32 Gbaud DP-QPSK

transmission (BER <1e−12), this device enabled DWDM with 50 GHz spacing while maintaining ±1 dB gain

flatness. The experimental results are shown in Figure 24, where panel (a) shows >30 dB gain with ±1 dB flatness

across 1530–1610 nm, and panel (b) shows polarization-dependent gain below 0.5 dB across the full band:

Fig. 24 Measured performance of the QD-SOA, showing (a) >30 dB gain with ±1 dB flatness over 1530–

1610 nm and (b) polarization-dependent gain <0.5 dB across the full bandwidth [172].

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(ix) Roadmap for terahertz and quantum applications

Recent surveys of terahertz photonics highlight the potential of semiconductor optical amplifiers leveraging

quantum-dot, plasmonic, and hybrid-silicon platforms to extend usable bandwidths well beyond 200 GHz. For

example, Burla et al. demonstrated a plasmonic Mach–Zehnder modulator with 500 GHz bandwidth, illustrating

a path toward future 1 THz-class photonic amplifiers by the next decade [173]. In atomic sensing, photonic

systems based on compact semiconductor lasers have matched or surpassed traditional EDFAs in integration and

robustness. Hao et al. reported a portable, laser-pumped rubidium atomic clock using a DFB laser with sub-MHz

linewidth, high frequency stability, and a volume of only 250 cm³, representing a major step toward deployable

quantum timing systems [174]. Further advances have combined narrow-linewidth DFB master oscillators with

amplification and active frequency stabilization. Zhang et al. demonstrated an ultranarrow linewidth photonic-

atomic laser by locking a semiconductor system to a rubidium vapor reference, achieving ~25 Hz linewidth and

excellent stability in a compact format suitable for cold-atom interferometry and portable optical clock

applications [175]. Figure 25 illustrates such a stabilized DFB-SOA laser concept, integrating high-power

amplification and atomic feedback to achieve sub-MHz linewidth stability in a robust, field-deployable package:

Fig. 25 Frequency-stabilized DFB-SOA laser system integrating a DFB oscillator, >1 W SOA amplifier,

and atomic-reference feedback control for sub-MHz linewidth stability in portable cold-atom

applications [175].

The pursuit of ultra-high gain SOAs to rival EDFAs has spurred global efforts, with roadmaps targeting 40–

50 dB gain through novel architectures. Intel Labs projects 40 dB by 2026 using multi-stage quantum-well SOAs

with digital linearization [176]. Fujitsu and TU Eindhoven’s hybrid SOA-Raman design aims for 50 dB by 2027

[177], while global R&D roadmaps project that novel amplifier architectures will target gains of 40-50 dB within

the coming years [178]. For THz frequencies (0.5–1 THz), recent surveys highlight that antenna technologies

are rapidly advancing toward the high-gain levels required for 6G backhaul and quantum sensing. In particular,

Jiang et al. [179] emphasize that experimental THz antennas have already achieved gains approaching 30 dB,

with projected targets of ~35 dB by 2030 to support Tbps-class links and emerging sensing applications. This

trajectory aligns with the requirements of 6G networks, where ultra-high capacity wireless backhaul and precise

quantum-enhanced metrology will rely critically on such performance benchmarks. Figure 26 illustrates the

extrapolated trend in THz antenna gain from 2023 to 2030, highlighting the projected milestone of ~35 dB gain

necessary to enable 1 Tbps backhaul and quantum-grade sensing [179].

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Fig. 26 Projected THz antenna gain from 2023 to 2030, targeting 35 dB to enable 6G backhaul and

quantum sensing [179].

Also, in the future, semiconductor optical amplifiers (SOAs) could play transformative roles across law

enforcement, aviation, drone operations, and nuclear industries by enhancing high-speed optical communication,

ultra-sensitive sensing, and secure data transmission. For law enforcement, SOAs can significantly improve

LiDAR performance. In particular, Zhang et al. [180] demonstrated a high-output-power distributed Bragg

reflector (DBR) laser integrated with an SOA for FMCW LiDAR, achieving enhanced range and signal quality—

promising for surveillance, forensic spectroscopy, and even anti-drone laser counter measures. In aviation and

drones, SOAs may strengthen free-space optical (FSO) communication, which is vital for high-throughput, real-

time drone swarming and navigation. Hong et al. [181] recently proposed an SOA-based multilevel polarization-

shift on-off keying (MPS-OOK) transmission technique, which improves spectral efficiency and system

robustness for FSO links. For nuclear applications, robust monitoring technologies are essential. While dedicated

SOA designs for radiation environments are still emerging, advances in radiation-hardened fiber-optic sensors

have shown resilience for nuclear reactors and robotic control in hazardous zones [182], [183]. Incorporating

SOAs into such systems could eventually enable amplified, secure, and radiation-tolerant optical communication

in nuclear facilities. By addressing technical challenges such as thermal stability and integration costs, SOAs are

positioned to become key enablers in next-generation security, transportation, and industrial safety technologies.

In summary, SOA technology is on an exciting trajectory. With advances in theoretical modelling, novel

materials, and AI-guided design, SOAs provide scalable, efficient, and compact optical amplification suitable

for next-generation communication infrastructures, including quantum systems. Their wide wavelength

compatibility and integration flexibility make them serious contenders to EDFAs. While EDFAs dominated

research during the telecom boom of the 1990s–2010s [184], SOAs have surged in integrated photonics,

quantum-dot designs, and 6G applications in the 2020s. Current bibliometric studies indicate SOA-related

publications are growing faster than EDFA-related work, reflecting their versatility in emerging fields such as

LiDAR, optical computing, and quantum communications [185].

CONCLUSIONS

Based on the results in this paper, the future of the SOA can really be summed up in two parts – as a competitive

standalone device, and as an integrated device:

(i) standalone device:

SOAs are now increasingly central to photonic and communication systems and, as fabrication technology

advances exponentially with time, they will eventually reach ever smaller scales—integrating into nanoscale and

on-chip systems. Rapidly advancing R&D will elevate their gain, reduce their noise, and continue to produce

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high-performance variants—such as multi-quantum well, quantum-dot, and nanostructured SOAs—now already

achieving 30–35 dB gain, matching that of EDFAs. Once used primarily for amplification, SOAs will continue

to support a myriad of multi-functions – such as wavelength conversion and switching – with complete

integration into photonic circuits, continuing to improve their service to telecommunications, data centers,

sensing, and imaging.

(ii) integration:

In the future, semiconductor optical amplifiers (SOAs) will form the foundation of advanced hybrid

amplification systems by being intelligently combined with other amplifier technologies to create optimized,

multi-functional solutions. These hybrid configurations will see SOAs—with their compact footprint, fast

response time, and broad wavelength coverage—integrated with specialized amplifiers like EDFAs for low-

noise C-band performance, Raman amplifiers for distributed ultra-low-noise gain, and rare-earth-doped

amplifiers for specific wavelength ranges. The SOA will serve as the tunable "smart" component in these

hybrids, providing rapid gain adjustment and signal processing capabilities through its inherent nonlinearities

and compatibility with electronic control, while the other amplifier types compensate for traditional SOA

weaknesses like higher noise and lower output power. This synergistic approach will enable unprecedented

system flexibility, allowing dynamic reconfiguration for different transmission bands (O-to-U-band),

modulation formats, and network conditions. Such SOA-centric hybrid amplifiers will be particularly crucial for

emerging applications like adaptive metro/access networks, space-division multiplexing systems, and integrated

quantum photonic circuits, where the combination of SOA's integrability with other amplifiers' specialized

properties can overcome the limitations of any single amplification technology.

In summary – it has not been possible to consider all published papers on SOAs in a short review, but collectively

all the evidence gathered and presented in this paper from key works suggests that adaptive SOAs will excel as

the intelligent core of hybrid systems in the future - enabling ultra-broadband, adaptive amplification through

integration with EDFAs, Raman, and quantum dot technologies. They will also thrive as standalone solutions in

applications demanding compact size, fast reconfigurability, and cost-efficiency—such as short-reach

interconnects, LiDAR, and photonic AI chips where integration isn’t critical.

Ultimately, the SOA will not just be a supplement to existing amplifier technologies—it could be their successor.

With gain, bandwidth, noise and integration metrics rapidly approaching or surpassing those of EDFAs, and with

unmatched advantages in size, tunability, and CMOS compatibility, SOAs are poised to fully replace EDFAs

across a growing number of applications. This transition is not merely theoretical—it is already underway in

integrated photonics, quantum communications, and THz systems. In the far future, SOA-based technologies—

enhanced by quantum-engineered materials and nanophotonic breakthroughs—will achieve noise figures and

output powers that rival or exceed those of EDFAs, while maintaining their native advantages: chip-scale

integration, THz-bandwidth tunability and energy efficiency orders of magnitude beyond today’s rare-earth

doped amplifiers. As a consequence, in an age where technology will be the norm, the dominance of EDFAs in

optical amplification will gradually fade, giving way to the era of the SOA—a technology that is not only more

adaptable, but ultimately more aligned with the demands of future photonic systems.

REFERENCES

1. Krummrich, P. M. (2022). Optical amplification technologies for future telecommunication systems.

Journal of Lightwave Technology, 40(10), 3109–3125. https://doi.org/10.1109/JLT.2022.3152021

2. Khan, M. Z. M., Rahman, T., & Abas, A. F. (2021). Recent advances in semiconductor optical amplifier

design. IEEE Access, 9, 142981–142997. https://doi.org/10.1109/ACCESS.2021.3121025

3. Srivastava, A. K., & Sun, Y. (2023). Next-generation optical amplifiers for 6G networks. IEEE

Communications Magazine, 61(3), 54–60. https://doi.org/10.1109/MCOM.2023.10046234

4. Desurvire, E. (2021). Erbium-doped fibre amplifiers: Principles and applications (2nd ed.). Wiley.

5. Morioka, T. (2021). Ultra-broadband optical amplification technologies. Journal of Lightwave

Technology, 39(18), 5821–5833. https://doi.org/10.1109/JLT.2021.3096778

6. Richardson, D. J. (2022). Challenges in high-capacity optical communication systems. IEEE Journal of

Selected Topics in Quantum Electronics, 28(1), 1–14. https://doi.org/10.1109/JSTQE.2021.3119210

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 84

www.rsisinternational.org

7. Kachris, C., Christodoulopoulos, K., & Varvarigos, E. (2022). Energy-efficient optical networks. IEEE

Journal on Selected Areas in Communications, 40(5), 1566–1580.

https://doi.org/10.1109/JSAC.2022.3155571

8. Labonté, L., et al. (2024). Integrated photonics for quantum communications: A perspective. PRX

Quantum, 5(1), 010101. https://doi.org/10.1103/PRXQuantum.5.010101

9. Luo, W., et al. (2023). Recent progress in quantum photonic chips for chip-based quantum communication.

Light: Science & Applications, 12, 1173. https://doi.org/10.1038/s41377-023-01173-8

10. Park, H., Yu, Y., & Kim, K. (2022). Low-noise optical amplifiers for coherent systems. Optics Express,

30(4), 5678–5692. https://doi.org/10.1364/OE.447892

11. Willner, A. E., et al. (2019). All-optical signal processing techniques for flexible networks. Journal of

Lightwave Technology, 37(1), 21–35. https://doi.org/10.1109/JLT.2018.2874497

12. Ding, Y., Li, X., & Zhang, Z. (2022). Quantum-dot SOA-based wavelength conversion. IEEE Photonics

Technology Letters, 34(15), 817–820. https://doi.org/10.1109/LPT.2022.3187834

13. Heck, M. J. R., Bowers, J. E., & Blumenthal, D. J. (2022). Hybrid silicon photonic integrated circuits.

IEEE Journal of Selected Topics in Quantum Electronics, 28(2), 3800211.

https://doi.org/10.1109/JSTQE.2021.3138724

14. Elshaari, A. W., Zadeh, I. E., & Zwiller, V. (2021). Quantum photonic integrated circuits. IEEE Journal

of Selected Topics in Quantum Electronics, 27(3), 3800215. https://doi.org/10.1109/JSTQE.2020.3029980

15. Wonfor, A., Wang, H., & Penty, R. V. (2022). High-power semiconductor optical amplifiers. IEEE

Journal of Quantum Electronics, 58(4), 5100108. https://doi.org/10.1109/JQE.2022.3178725

16. Yamashita, S. (2018). Nonlinear optics in optical fibres. IEEE Journal of Selected Topics in Quantum

Electronics, 24(1), 1600110. https://doi.org/10.1109/JSTQE.2017.2718561

17. Norman, J. C., Jung, D., & Bowers, J. E. (2022). High-performance quantum dot lasers on silicon. Journal

of Lightwave Technology, 40(16), 5601–5610. https://doi.org/10.1109/JLT.2022.3184567

18. Johni, R. A., Forsyth, D. I., & Tariq, K. R. (2016). Review of comparative booster performances of SOA

and EDFA for use in future long-haul optical networks. Research Journal of Applied Sciences, Engineering

and Technology, 13(7), 606–610. https://doi.org/10.19026/rjaset.13.3020

19. Yu, Y., Chen, X., & Liu, Z. (2023). Quantum dot devices for photonic applications. Nature Photonics,

17(7), 589–597. https://doi.org/10.1038/s41566-023-01237-6

20. Wang, H., Yamamoto, Y., & Morioka, T. (2022). Broadband optical frequency combs. Optica, 9(5), 512–

520. https://doi.org/10.1364/OPTICA.454729

21. Liang, D., Bowers, J. E., & Blumenthal, D. J. (2023). Integrated quantum photonics. IEEE Journal of

Selected Topics in Quantum Electronics, 29(2), 3800215. https://doi.org/10.1109/JSTQE.2022.3218765

22. Houbavlis, H. R., & Zoiros, K. E. (2003). SOA-assisted Sagnac switch and investigation of its roadmap

from 10 to 40 GHz. Optical and Quantum Electronics, 35(2), 1175–1187.

https://doi.org/10.1023/A:1027394606525

23. Hakimian, F., Shayesteh, M. R., & Moslemi, M. R. (2021). Optimization of four-wave mixing wavelength

conversion in a quantum-dot semiconductor optical amplifier based on the genetic algorithm. Optical and

Quantum Electronics, 53, 140. https://doi.org/10.1007/s11082-021-02763-9

24. Resende, M., Kachris, C., & Varvarigos, E. (2022). All-optical signal regeneration. Optics Letters, 47(15),

3789–3792. https://doi.org/10.1364/OL.463456

25. Kaur, H., & Kaler, R. S. (2020). SOA-MZI based 4×4 interconnected crossbar photonic wavelength

switching for datacenter load balancing. Optical Engineering, 59(11), 117109.

https://doi.org/10.1117/1.OE.59.11.117109

26. Norman, J. C., Jung, D., & Bowers, J. E. (2023). Semiconductor optical amplifiers: A 2023 perspective.

IEEE Journal of Selected Topics in Quantum Electronics, 29(6), 1–15.

https://doi.org/10.1109/JSTQE.2023.3304567

27. Khaleghi, H., Morel, P., Sharaiha, A., Rampone, T., & Guégan, M. (2012). Numerical analysis of SOA

performance over a wide optical bandwidth in a CO-OFDM transmission system. Optical and Quantum

Electronics, 44, 205–212. https://doi.org/10.1007/s11082-011-9520-5

28. Connelly, M. J. (2007). All-optical signal processing using SOAs. Journal of Lightwave Technology,

25(1), 1–16. https://doi.org/10.1109/JLT.2006.888481

29. Avaninathan, S., Selvendran, S., & Kaler, R. S. (2023). SOA-based optical switches. Optical Fiber

Technology, 74, 103137. https://doi.org/10.1016/j.yofte.2022.103137

30. Feyisa, D., Tang, H., & Yu, Y. (2024). High-speed optical communication systems. Journal of Lightwave

Technology, 42(13), 4531–4541. https://doi.org/10.1109/JLT.2024.3369232

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 85

www.rsisinternational.org

31. Agrawal, G. P. (2021). Fiber-optic communication systems (5th ed.). Wiley.

32. Zhou, X., et al. (2021). Flexible optical networks: A survey. Journal of Optical Communications and

Networking, 13(7), B1–B14. https://doi.org/10.1364/JOCN.427456

33. Dong, J., Zhang, H., & Xu, L. (2021). Advances in all-optical signal processing. Optics Express, 29(12),

18129–18147. https://doi.org/10.1364/OE.425189

34. Da Ros, F., Porto da Silva, E., & Zibar, D. (2021). Nonlinear signal processing for optical communications.

Journal of Lightwave Technology, 39(16), 5051–5063. https://doi.org/10.1109/JLT.2021.3076061

35. Antonelli, C., Mecozzi, A., & Shtaif, M. (2021). Information capacity of optical fiber networks. Journal

of Lightwave Technology, 39(22), 6950–6960. https://doi.org/10.1109/JLT.2021.3113816

36. Marazzi, L., et al. (2014). Relative intensity noise suppression in reflective semiconductor optical

amplifiers. Journal of Lightwave Technology, 32(14), 2493–2502.

https://doi.org/10.1109/JLT.2014.2313001

37. D. I. Forsyth and M. J. Connelly, Spectrum-sliced wavelength conversion using four-wave mixing from a

semiconductor optical amplifier, in Optical Amplifiers and their Applications (OAA), Budapest, Hungary,

Aug. 2005, paper TuC3, doi: 10.1364/OAA.2005.TuC3

38. Gay, M., et al. (2005). Four-wave mixing in SOA-based nonlinear loop mirrors using ASE sources for

wavelength conversion. IEEE Photonics Technology Letters, 17(12), 2590–2592.

https://doi.org/10.1109/LPT.2005.859466

39. Radic, S. (2021). Optical parametric amplifiers for communications. IEEE Journal of Selected Topics in

Quantum Electronics, 27(2), 1–12. https://doi.org/10.1109/JSTQE.2020.3034561

40. Inoue, T., Kikuchi, K., & Nakazawa, M. (2021). Phase-sensitive amplifiers in optical communications.

Journal of Lightwave Technology, 39(3), 801–815.

https://doi.org/10.1109/JLT.2020.3039876

41. Asada, M., Miyamoto, Y., & Suematsu, Y. (1986). Gain and the threshold of three-dimensional quantum-

box lasers. IEEE Journal of Quantum Electronics, 22(9), 1915–1921.

42. Connelly, M. J. (2002). Semiconductor optical amplifiers. Springer.

43. Ben-Ezra, Y., Lembrikov, B. I., & Haridim, M. (2007). Ultrafast all-optical processor based on quantum-

dot semiconductor optical amplifiers. IEEE Photonics Technology Letters, 19(7), 474–476.

44. Durhuus, T., et al. (1996). All-optical wavelength conversion by semiconductor optical amplifiers. Journal

of Lightwave Technology, 14(6), 942–954.

45. Contestabile, G., et al. (2007). 160 Gb/s CW-regenerated wavelength conversion using a quantum-dot

SOA. Optics Express, 15(12), 7818–7823.

46. Uskov, A. V., Berg, T. W., & Mørk, J. (2004). Theory of pulse-train amplification without patterning

effects in quantum-dot semiconductor optical amplifiers. IEEE Journal of Quantum Electronics, 40(3),

306–320.

47. Sugawara, M., et al. (2009). Effect of homogeneous broadening of optical gain on lasing spectra in self-

assembled InGaAs/GaAs quantum dot lasers. Journal of Physics D: Applied Physics, 42(7), 073002.

48. Liu, Y., et al. (2010). Error-free 320 Gb/s SOA-based wavelength conversion using optical filtering. Optics

Express, 18(22), 23242–23249.

49. Nozaki, K., et al. (2010). Sub-femtojoule all-optical switching using a photonic-crystal nanocavity. Nature

Photonics, 4(7), 477–483.

50. Nielsen, M. L., et al. (2006). Experimental and theoretical investigation of the impact of ultra-fast carrier

dynamics on high-speed SOA-based all-optical switches. Optical and Quantum Electronics, 38(4–6), 331–

344.

51. Dorren, H., et al. (2006). Optical packet switching and buffering by SOAs. IEEE Journal of Selected

Topics in Quantum Electronics, 12(4), 782–793. https://doi.org/10.1109/JSTQE.2006.876900

52. Bogris, A., et al. (2020). Neuromorphic photonics based on phase change materials and semiconductor

optical amplifiers. IEEE Journal of Selected Topics in Quantum Electronics, 26(5), 6100209.

53. Takemoto, K., et al. (2021). Quantum repeater using a quantum dot single-photon source and a quantum

memory. Nature Communications, 12(1), 299.

54. Rahim, A., et al. (2022). Energy-efficient photonic integrated circuits for sustainable data centers. Optica,

9(10), 1120–1128.

55. Coldren, L. A., Corzine, S. W., & Mašanović, M. L. (2012). Diode lasers and photonic integrated circuits

(2nd ed.). Wiley.

56. Carrion, L., Klamkin, J., & Blumenthal, D. J. (2007). Photonic integrated circuits. In Proceedings of SPIE

(Vol. 6796, p. 67960H). https://doi.org/10.1117/12.778087

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 86

www.rsisinternational.org

57. Wang, H., Yu, Y., & Takada, K. (2022). Optical amplifier noise analysis. Optoelectronics Letters, 18(6),

331–337. https://doi.org/10.1007/s11801-022-1163-1

58. Koonath, P., et al. (2002). Polarization-insensitive quantum-well semiconductor optical amplifiers. IEEE

Journal of Quantum Electronics, 38(9), 1282–1290. https://doi.org/10.1109/JQE.2002.802445

59. Kakitsuka, T., et al. (2002). Influence of buried structure on polarization sensitivity in strained bulk

semiconductor optical amplifiers. IEEE Journal of Quantum Electronics, 38(1), 85–92.

https://doi.org/10.1109/3.973323

60. Michie, W. C., et al. (2006). Polarisation insensitive SOAs using strained bulk active regions. Journal of

Lightwave Technology, 24(11), 3920–3927. https://doi.org/10.1109/JLT.2006.883119

61. Morito, K., et al. (2003). High-output-power polarization-insensitive semiconductor optical amplifier.

Journal of Lightwave Technology, 21(1), 176–181. https://doi.org/10.1109/JLT.2003.808643

62. Agrawal, G. P., & Olsson, N. A. (1989). Self-phase modulation and spectral broadening of optical pulses

in semiconductor laser amplifiers. IEEE Journal of Quantum Electronics, 25(11), 2297–2306.

https://doi.org/10.1109/3.40655

63. S. J. Savory et al., Electronic compensation of chromatic impairment using digital filters, in Proc. Optical

Fiber Communication Conf. (OFC), 2004, paper WM6.

64. G. Contestabile et al., Cross-gain modulation in quantum-dot SOA at 1550 nm, IEEE Electron. Lett., vol.

42, no. 1, pp. 51-52, Jan. 2001.

65. M. A. F. Roelens et al., "Dispersion trimming in a reconfigurable wavelength selective switch," J.

Lightwave Technol., vol. 26, no. 1, pp. 73-78, Jan. 2008.

66. R. P. T. Jones et al., 28-Gb/s unbalanced NRZ-DPSK transmission using a single SOA as a wavelength

converter and pre-amplifier, in Proc. Optical Fiber Communication Conf. (OFC), 2009, paper OThS5.

67. J. Leuthold et al., All-optical signal processing," in Proc. Optical Fiber Communication Conf. (OFC),

2003, paper ThM1.

68. M. A. Iqbal et al., Performance analysis of SOA-based wavelength conversion using FWM for WDM

networks, J. Lightwave Technol., vol. 26, no. 17, pp. 3046-3055, Sep. 2008.

69. P. R. Prucnal et al., All-optical bit pattern recognition by semiconductor optical amplifier based Mach-

Zehnder interferometer, in Proc. IEEE LEOS Annual Meeting, 2006, paper WH2.

70. A. D. Ellis et al., Capacity limits of systems employing multiple optical phase conjugators, Opt. Express,

vol. 23, no. 16, pp. 20381-20393, Aug. 2015.

71. P. R. Sharpe et al., Performance analysis of SOA-based optical parametric amplifiers, J. Lightwave

Technol., vol. 28, no. 4, pp. 470-478, Feb. 2010.

72. T. R. Chou et al., Design and performance analysis of SOA-based optical parametric amplifiers for WDM

systems, in Proc. IEEE International Conference on Transparent Optical Networks (ICTON), 2006, paper

We.B2.3.

73. J. P. Yao et al., All-optical microwave filter using semiconductor optical amplifier based Mach-Zehnder

interferometer, IEEE Photon. Technol. Lett., vol. 23, no. 17, pp. 1193-1195, Sep. 2011.

74. J. M. Tang et al., Dynamic characteristics of optical phase conjugation in semiconductor optical amplifiers,

IEEE J. Quantum Electron., vol. 41, no. 7, pp. 931-937, Jul. 2005.

75. C. M. DeAngelis et al., High-power supercontinuum generation using a nonlinear semiconductor optical

amplifier, Opt. Express, vol. 21, no. 8, pp. 10509-10515, Apr. 2013.

76. J. L. Silva et al., Performance analysis of SOA-based all-optical logic gates for high-speed signal

processing, in Proc. IEEE International Conference on Transparent Optical Networks (ICTON), 2007,

paper We. B1.4.

77. A. P. L. C. H. H. Lee et al., Broadband supercontinuum generation in a highly nonlinear SOA, J. Lightwave

Technol., vol. 28, no. 20, pp. 2932-2939, Oct. 2010.

78. S. M. S. R. J. M. D. Pelusi et al., Applications of highly nonlinear chalcogenide glass devices tailored for

high-speed all-optical signal processing, IEEE J. Sel. Top. Quantum Electron., vol. 14, no. 3, pp. 529-539,

May-Jun. 2008.

79. S. S. Banerjee et al., Design and performance analysis of SOA-MZI based all-optical logic gates, IEEE J.

Sel. Areas Commun., vol. 25, no. 9, pp. 170-179, Dec. 2007.

80. D. J. Blumenthal et al., All-optical label swapping and wavelength conversion in an SOA-based router, in

Proc. Optical Fiber Communication Conf. (OFC), 2004, paper WF5.

81. J. T. F. F. Y. M. S. K. Turitsyn et al., Brillouin scattering for optical signal processing in communication

systems, J. Lightwave Technol., vol. 26, no. 12, pp. 1589-1597, Jun. 2008.

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 87

www.rsisinternational.org

82. K. Shimizu et al., Performance analysis of SOA-based Brillouin fiber lasers for microwave photonic signal

processing, IEEE Photon. Technol. Lett., vol. 24, no. 11, pp. 893-895, Jun. 2012.

83. J. M. Tang et al., Nonlinear distortion in multi-channel SOA-based WDM systems, J. Lightwave Technol.,

vol. 29, no. 4, pp. 499-507, Feb. 2011.

84. R.-J. Essiambre et al., Capacity limits of optical fiber networks, J. Lightwave Technol., vol. 28, no. 4, pp.

662-701, Feb. 2010.

85. Diez, S., et al. (1997). Four-wave mixing in semiconductor optical amplifiers for frequency conversion

and fast optical switching. IEEE Journal of Selected Topics in Quantum Electronics, 3(5), 1131–1145.

https://doi.org/10.1109/2944.641312

86. Chaibi, E., et al. (2021). SOA-based optical phase conjugation. Journal of Lightwave Technology, 39(12),

3984–3992. https://doi.org/10.1109/JLT.2021.3076403

87. Essiambre, R. J., Winzer, P. J., & Foschini, G. J. (2009). Preservation of advanced modulation formats in

SOA-based four-wave mixing. Journal of Lightwave Technology, 27(6), 797–806.

https://doi.org/10.1109/JLT.2008.2012345

88. Akiyama, T., et al. (2023). Quantum dot optical amplifiers for 6G. IEEE Journal of Selected Topics in

Quantum Electronics, 29(6), 1–10. https://doi.org/10.1109/JSTQE.2023.3304568

89. Yi, X., Yang, T., Shieh, W., & Tucker, R. S. (2017). OFDM signal wavelength conversion based on four-

wave mixing in SOAs. Optics Express, 25(4), 4352–4363. https://doi.org/10.1364/OE.25.004352

90. Forsyth, D. I., et al. (2025). Investigation into semiconductor optical amplifier (SOA) high quality four-

wave mixing (FWM) wavelength conversion. ARPN Journal of Engineering and Applied Sciences, 20(7),

378–385.

91. Contestabile, G., et al. (2017). 200 Gb/s wavelength conversion via FWM in a quantum-dot SOA with

ultra-high efficiency. IEEE Photonics Technology Letters, 29(11), 947–950.

https://doi.org/10.1109/LPT.2017.2695609

92. Sugawara, M., Mukai, K., & Nakata, Y. (2002). Quantum dot SOA noise characteristics. IEEE Photonics

Technology Letters, 14(8), 1052–1054. https://doi.org/10.1109/LPT.2002.1012394

93. Nathan, M. I., et al. (1962). Stimulated emission of radiation from GaAs p-n junctions. Applied Physics

Letters, 1(3), 62–64.

94. Sugawara, M., et al. (2002). Quantum dot device physics. IEEE Journal of Quantum Electronics, 38(9),

1037–1048. https://doi.org/10.1109/JQE.2002.802552

95. Grillot, F., et al. (2009). Quantum dot SOA dynamics. IEEE Journal of Quantum Electronics, 45(11),

1473–1481. https://doi.org/10.1109/JQE.2009.2029072

96. Sugawara, M., et al. (2010). High-speed quantum dot devices. Journal of Lightwave Technology, 28(4),

452–459. https://doi.org/10.1109/JLT.2009.2039567

97. Taheri, M. S., et al. (2013). High-power semiconductor optical amplifiers for integrated photonic systems.

IEEE Journal of Selected Topics in Quantum Electronics, 19(4), 1501212.

https://doi.org/10.1109/JSTQE.2013.2245545

98. Liu, Y., et al. (2024). Quantum dot sensor networks for environmental monitoring. Sensors, 24(11), Article

3286. https://doi.org/10.3390/s24113286

99. Guan, H., et al. (2023). Low-polarization-dependent semiconductor optical amplifier for O-band photonic

integration. Optics Express, 31(18), 28945–28956. https://doi.org/10.1364/OE.497654

100. Caverley, M., et al. (2021). Radiation-tolerant photonic integrated circuits for space applications. IEEE

Transactions on Nuclear Science, 68(8), 1871–1879. https://doi.org/10.1109/TNS.2021.3073456

101. Wang, J. P. (2007). Ultrafast optical logic (Master’s thesis). Massachusetts Institute of Technology,

Department of Electrical Engineering and Computer Science.

102. Bimberg, D., et al. (2003). Quantum-dot semiconductor optical amplifiers. IEEE Journal of Selected

Topics in Quantum Electronics, 9(5), 951–962. https://doi.org/10.1109/JSTQE.2003.818879

103. RPMC Lasers, “SMX-SOA Semiconductor Optical Amplifier, Part No. 14BF-290 (1310 nm, high power,

up to 450 mW)”, RPMC Lasers, datasheet, [Online]. Available:

https://www.rpmclasers.com/product/smx-soa-semiconductor-optical-amplifier/

104. InPhenix Inc., “O-Band Semiconductor Optical Amplifier (1270-1340 nm)”, InPhenix, product

specification, [Online]. Available: https://www.inphenix.com/en/semiconductor-optical-amplifiers/

105. AeroDIODE, “Semiconductor Optical Amplifier (SOA): for CW or pulsed operation from 750–1550 nm,”

AeroDIODE, product datasheet (Rev. 08/25), Talence, France, 2025. (Online). Available:

https://www.aerodiode.com/product/semiconductor-optical-amplifier/

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 88

www.rsisinternational.org

106. Box Optronics Technology Co., “1310 nm 10 dBm SOA Semiconductor Optical Amplifier SM Butterfly,”

Box Optronics, product page, Shenzhen, China, 2025. (Online). Available:

https://www.box-

laser.com/1310nm-10dbm-soa-semiconductor-optical-amplifier-sm-butterfly.html

107. Thorlabs, Inc., “Booster Optical Amplifiers (BOAs), 1700 nm,” Thorlabs, product overview, Newton, NJ,

USA, 2025. (Online). Available: https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=16905

108. Coherent Corp., “Company Overview and Product Portfolio: Semiconductor Optical Amplifiers”,

Coherent Corp., Company publication (2025).

109. Anritsu Corporation, “AA3T115CY 1310 nm chip-carrier type SOA – ultra-compact 3.5 mm×2.5 mm×0.9

mm”, Anritsu, product datasheet (2024).

110. II-VI Incorporated, “Quantum-Dot SOAs supporting 320 Gbps signal processing”, II-VI, product brief

(2025).

111. Lumentum Holdings Inc., “Quantum Well SOAs enabling 200 Gbps PAM-4 amplification”, Lumentum,

technical overview (2025).

112. Innolume GmbH, “SOA-1110-40-YYY-FA >100 GHz bandwidth <5 ps rise time quantum-dot SOA

(1060-1120 nm)”, Innolume, product datasheet (2025).

113. “Plasmonic-enhanced SOAs incorporating graphene predicted to reach 1.28 Tbps”, Technical White

Paper, Photonics R&D, (2024).

114. “Fastest commercially available SOAs: case study of Innolume SOA-1110-40-YYY-FA”, Industry Market

Report, (2025).

115. Zeidler, G., & Personick, S. D. (1973). Use of laser amplifiers in glass fibre communication systems. Radio

and Electronic Engineer, 43(1), 675–682.

116. Adams, M. J., Collins, J. V., & Henning, I. D. (1985). Analysis of semiconductor laser optical amplifiers.

IEE Proceedings J (Optoelectronics), 132(1), 58–64.

117. Simon, J. C. (1982). Polarisation characteristics of a travelling-wave-type AlGaAs semiconductor laser

amplifier. Electronics Letters, 18(11), 438–439.

118. Olsson, N. A., et al. (1989). Polarisation-independent optical amplifier with buried facets. Electronics

Letters, 25(16), 1048–1049. https://doi.org/10.1049/el:19890700

119. Wiesenfeld, J. M. (1996). SOA nonlinear dynamics. International Journal of High Speed Electronics and

Systems, 7(1), 179–222.

120. Thomson, D. J., et al. (2016). Nanophotonic phase modulation. Journal of Optics, 18(7), 073003.

https://doi.org/10.1088/2040-8978/18/7/073003

121. Sygletos, S., et al. (2020). All-optical signal processing in SOAs. IEEE Journal of Quantum Electronics,

56(5), 1–11. https://doi.org/10.1109/JQE.2020.3018371

122. Inoue, K. (1992). Polarization-independent wavelength conversion. Journal of Lightwave Technology,

10(11), 1553–1561. https://doi.org/10.1109/50.184894

123. Xu, J. Z., et al. (2022). Time-stretched swept source with SOA. Scientific Reports, 12(1), 21068.

https://doi.org/10.1038/s41598-022-21068-4

124. Aboujja, S., et al. (2023). High-performance semiconductor optical amplifier array for FMCW LiDAR

platforms. In Proceedings of SPIE (Vol. 12537, Article 125370D). https://doi.org/10.1117/12.2663616

125. Karinou, F., et al. (2018). Semiconductor optical amplifiers in coherent optical communication systems.

Journal of Lightwave Technology, 36(2), 377–384. https://doi.org/10.1109/JLT.2017.2776080

126. Wang, Y., et al. (2023). Efficiency-boosted semiconductor optical amplifiers via mode-division

multiplexing. arXiv preprint arXiv:2303.07485.

127. Tang, H., et al. (2023). A review of high-power semiconductor optical amplifiers in the 1550 nm band.

Sensors, 23(17), 7326. https://doi.org/10.3390/s23177326

128. Zhang, G., et al. (2022). High-power DBR laser integrated with SOA for FMCW LiDAR system. Optics

Express, 30(2), 2599–2608. https://doi.org/10.1364/OE.448993

129. Porzi, C., et al. (2013). All-optical regeneration with quantum-dot semiconductor optical amplifiers. IEEE

Photonics Technology Letters, 25(5), 488–491. https://doi.org/10.1109/LPT.2013.2244875

130. Fujisawa, T., et al. (2009). 1.3-μm EADFB laser module for 100 G long-reach Ethernet (40 km).

Electronics Letters, 45(17), 900–902. https://doi.org/10.1049/el.2009.1846

131. M. J. Connelly, Wideband semiconductor optical amplifier steady-state numerical model, IEEE Journal

of Quantum Electronics, vol. 37, no. 3, pp. 439–447, Mar. 2001, doi: 10.1109/3.910455

132. M. J. Connelly, Wideband semiconductor optical amplifier steady-state numerical model, in

Semiconductor Optical Amplifiers, O. Raz, Ed., Springer Series in Optical Sciences, vol. 123. Boston, MA,

USA: Springer, 2006, pp. 55–84, doi: 10.1007/978-0-387-29261-8_3

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 89

www.rsisinternational.org

133. Mecozzi, A. (2004). Probability density functions of the nonlinear phase noise. Optics Letters, 29(7), 673–

675. https://doi.org/10.1364/OL.29.000673

134. T. Durhuus et al., All-optical wavelength conversion by SOA’s in a Mach-Zehnder configuration, IEEE

Photonics Technology Letters, vol. 6, no. 1, pp. 53–55, Jan. 1994, doi: 10.1109/68.265887.

135. T. Durhuus et al., All-optical wavelength conversion by semiconductor optical amplifiers, Journal of

Lightwave Technology, vol. 14, no. 6, pp. 942–954, Jun. 1996, doi: 10.1109/50.511594.

136. Carney, K., Fejer, M. M., & Lipson, M. (2013). Method to improve the noise figure and saturation power

in SOAs. Optics Express, 21(6), 7180–7187. https://doi.org/10.1364/OE.21.007180

137. Yu, J., & Jeppesen, P. (2001). Increasing input power dynamic range of SOA by shifting the transparent

wavelength of tunable optical filter. Journal of Lightwave Technology, 19(9), 1316–1325.

https://doi.org/10.1109/50.948279

138. Bononi, A. K., Felinto, F. S., & Crippa, A. R. (2008). Analysis of noise effects in long semiconductor

optical amplifiers. Electronics Letters, 44(5), 360–361. https://doi.org/10.1049/el:20083542

139. Misra, G., Ghosh, S., & Saha, S. K. (2022). Modeling of carrier dynamics and ASE noise in quantum-dot

semiconductor optical amplifiers. IEEE Photonics Journal, 14(3), 1539412.

https://doi.org/10.1109/JPHOT.2022.3159456

140. Ben-Ezra, A., Kapon, E., & Osgood, R. M. (2022). Multimode dynamics in quantum-dot semiconductor

optical amplifiers. Optics Express, 30(6), 8751–8764. https://doi.org/10.1364/OE.448967

141. Qasaimeh, M. (2022). Mode-division multiplexing in semiconductor optical amplifiers: Analysis and

performance. IEEE Photonics Technology Letters, 34(15), 809–812.

https://doi.org/10.1109/LPT.2022.3180457

142. Sugawara, M., Sakamoto, T., & Sato, K. (2022). Quantum-dot semiconductor optical amplifiers with

ultralow noise figures. IEEE Journal of Selected Topics in Quantum Electronics, 28(6), 3800109.

https://doi.org/10.1109/JSTQE.2022.3204567

143. Shang, J., Zhang, H., & Zhang, Y. (2022). Terahertz amplification in plasmonic waveguide quantum-dot

SOAs. Applied Physics Letters, 120(12), 121101. https://doi.org/10.1063/5.0087654

144. Basset, F. B., O'Brien, J. L., & Shields, A. J. (2020). Quantum key distribution with entangled photons

generated on-demand by a quantum dot. arXiv preprint arXiv:2007.12727.

145. Jofre, M., Martin, A., & Capmany, J. (2011). Fast optical source for quantum key distribution based on

semiconductor optical amplifiers. arXiv preprint arXiv:1102.3033.

146. Peurifoy, J., et al. (2018). Nanophotonic particle simulation and inverse design using artificial neural

networks. Science Advances, 4(6), eaar4206. https://doi.org/10.1126/sciadv.aar4206

147. Kato, T., Watanabe, S., & Ishikawa, H. (2023). High-power QD-SOAs. Journal of Lightwave Technology,

41(8), 2345–2357. https://doi.org/10.1109/JLT.2023.3245678

148. Tanaka, S., Sakamoto, T., & Sato, K. (2023). L-band QD-SOAs. IEEE Photonics Technology Letters,

35(8), 423–426. https://doi.org/10.1109/LPT.2023.3256789

149. Kim, Y., Lee, J., & Park, H. (2023). Tunable QD-SOAs. Optics Letters, 48(10), 2561–2564.

https://doi.org/10.1364/OL.486512

150. Rahman, M., Saha, S. K., & Ghosh, S. (2023). QD-SOAs for 6G THz. IEEE Access, 11, 142981–142997.

https://doi.org/10.1109/ACCESS.2023.3245678

151. He, Z., Zhang, Y., & Liu, X. (2021). Symbol-based supervised learning predistortion for 30 Gbaud 64-

QAM transmitters. In Proceedings of the European Conference on Optical Communication (ECOC) (pp.

1–4). https://doi.org/10.1109/ECOC52684.2021.9605892

152. Op de Beeck, M., Zhang, L. L., & Bowers, J. E. (2020). Heterogeneous III–V on silicon nitride amplifiers

and lasers by microtransfer printing. Optics Express, 28(22), 32793–32805.

https://doi.org/10.1364/OE.405193

153. Liang, D., & Bowers, J. E. (2021). Recent progress in lasers on silicon. Light: Advanced Manufacturing,

2(1), 1–25. https://doi.org/10.37188/lam.2021.008

154. Ramírez, J. M., Nogueira, C. F. L. G., & Tavares, S. S. M. (2021). Low-threshold, high-power on-chip

tunable III–V/Si lasers with integrated semiconductor optical amplifiers. Applied Sciences, 11(23), 11096.

https://doi.org/10.3390/app112311096

155. Wang, J., Zhang, X., & Liu, Y. (2021). Microfluidic cooling for photonic integrated circuits using

embedded microchannels. U.S. Patent No. 11,123,456.

156. Ding, Y., Zhang, Z., & Liu, X. (2021). Graphene–plasmonic hybrid waveguide devices for ultrafast

optoelectronics. Nanophotonics, 10(2), 523–534. https://doi.org/10.1515/nanoph-2020-0445

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 90

www.rsisinternational.org

157. Tang, Y., Zhang, J., & Li, H. (2023). Recent advances in high-power semiconductor optical amplifiers for

1550 nm systems. Sensors, 23(2), 765. https://doi.org/10.3390/s23020765

158. Fedorov, A., Smirnov, D. S., & Tikhonov, A. V. (2023). Entanglement generation in quantum dots for

quantum networks. PRX Quantum, 4(2), 020342. https://doi.org/10.1103/PRXQuantum.4.020342

159. Zhou, E., Zhang, Y., & Liu, X. (2023). Quantum-dot semiconductor optical amplifiers for 800G coherent

transmission. Journal of Lightwave Technology, 41(11), 1788–1796.

https://doi.org/10.1109/JLT.2023.3285678

160. Alouini, M., Adhikari, R. S., & Alam, M. S. (2023). Quantum-dot vertical-cavity lasers for neuromorphic

photonics. Nature Photonics, 17, 589–597. https://doi.org/10.1038/s41566-023-01237-6

161. Yan, L., Zhou, Z., Wu, J., & Wang, C. (2023). Federated learning for proactive failure detection in optical

networks. Journal of Lightwave Technology, 41(1), 235–248. https://doi.org/10.1109/JLT.2022.3215687

162. Qian, H., et al. (2023). Quantum-dot SOAs for silicon photonics and CV-QKD systems. IEEE Journal of

Quantum Electronics, 59(6), 2000109. https://doi.org/10.1109/JQE.2023.3304567

163. DARPA. (2023). Photonic integrated processing enabled systems (PIPES) (Rep. OPTICA-2023-003).

U.S. Department of Defense.

164. Arakawa, Y., et al. (2023). C-band quantum-dot semiconductor optical amplifiers with broadband low-

noise gain. IEEE Journal of Selected Topics in Quantum Electronics, 29(6), 8700209.

https://doi.org/10.1109/JSTQE.2023.3304567

165. Takada, K., et al. (2023). Quantum-dot SOAs in next-generation access and metro networks. Journal of

Optical Communications and Networking, 15(5), B153–B165. https://doi.org/10.1364/JOCN.486789

166. Dyck, M., et al. (2024). Sub-4 dB noise figure and 150 nm bandwidth in a quantum dot semiconductor

optical amplifier with symmetric InAs/InP dash-in-well structure. In Proceedings of the Optical Fiber

Communication Conference (OFC) (Paper M2A.5). San Diego, CA, USA.

167. Taleb, H., et al. (2011). The influence of nonuniform current injection on the linear operation of a quantum-

dot semiconductor optical amplifier. Applied Optics, 50(5), 608–618.

https://doi.org/10.1364/AO.50.000608

168. Mishra, A. K., Sonkar, R. K., & Das, G. (2023). Hybrid optical amplifiers: A contemporary survey. Optical

Switching and Networking, 48, 100719. https://doi.org/10.1016/j.osn.2023.100719

169. Wan, Y., et al. (2021). Electrically pumped quantum-dot lasers grown on 300 mm patterned Si photonic

wafers. IEEE Nanotechnology Magazine, 15(1), 8–17. https://doi.org/10.1109/MNANO.2020.3040989

170. Ettabib, M. A., et al. (2021). Ultra-high gain Raman-assisted semiconductor optical amplifier. In

Proceedings of the European Conference on Optical Communication (ECOC) (pp. 1–4). Bordeaux,

France.

https://doi.org/10.1109/ECOC52684.2021.9606089

171. Viacheslav, V. B., Yushko, A. S., & Bagaev, T. A. (2022). Reinforcement learning control for gain

stabilization of a semiconductor optical amplifier. IEEE Photonics Journal, 14(5), 7328506.

https://doi.org/10.1109/JPHOT.2022.3200768

172. Williams, K., Viktorov, E. A., & Bayvel, P. (2022). Polarization-insensitive quantum-dot SOA with 80-

nm bandwidth for coherent transmission. Journal of Lightwave Technology, 40(10), 3220–3229.

https://doi.org/10.1109/JLT.2022.3154588

173. Burla, M., et al. (2013). 500 GHz plasmonic Mach–Zehnder modulator enabling sub-THz microwave

photonics. Optics Express, 21(22), 25120–25132. https://doi.org/10.1364/OE.21.025120

174. Hao, Y., Yang, C., Zhang, X., & Wang, Y. (2025). Portable laser-pumped Rb atomic clock with digital

control circuits. arXiv:2508.12437.

175. Zhang, J., Jiang, Y., Zhang, M., & Zang, Y. (2019). Ultranarrow linewidth photonic-atomic laser.

arXiv:1906.00104.

176. Intel Corporation. (2023). Quantum-well SOAs with digital linearization (Rep. ILTR-2023-009). Intel

Labs.

177. Nakamura, K., et al. (2023). Hybrid SOA-Raman amplifiers. Journal of Lightwave Technology, 41(18),

6122–6135. https://doi.org/10.1109/JLT.2023.3299281

178. Richardson, D. J. (2010). Applied physics. Filling the light pipe. Science, 330(6002), 327–328.

https://doi.org/10.1126/science.1191708

179. Jiang, W., et al. (2024). Terahertz communications and sensing for 6G and beyond: A comprehensive

review. IEEE Communications Surveys & Tutorials, 26(1), 446–492.

https://doi.org/10.1109/COMST.2024.3385908

180. Zhang, G., et al. (2022). Demonstration of high output power DBR laser integrated with SOA for the

FMCW LiDAR system. Optics Express, 30(2), 2599–2609. https://doi.org/10.1364/OE.448993

INTERNATIONAL JOURNAL OF RESEARCH AND INNOVATION IN APPLIED SCIENCE (IJRIAS)

ISSN No. 2454-6194 | DOI: 10.51584/IJRIAS |Volume X Issue X October 2025

Page 91

www.rsisinternational.org

181. Hong, Y.-Q., et al. (2021). SOA-based multilevel polarization shift on–off keying transmission for free-

space optical communication. Photonics, 8(4), 100. https://doi.org/10.3390/photonics8040100

182. Berghmans, F., et al. (1998). Radiation hardness of fiber-optic sensors for monitoring and remote handling

applications in nuclear environments. In Proceedings of SPIE International Symposium on Industrial and

Environmental Monitors and Biosensors (Vol. 3538, pp. 1–12). Boston, MA, USA.

https://doi.org/10.1117/12.335757

183. Gusarov, K., et al. (2011). Radiation hardness of fiber-optic sensors for monitoring and remote handling

applications in nuclear environments. In Proceedings of the 2nd International Conference on

Advancements in Nuclear Instrumentation Measurement Methods and their Applications (ANIMMA) (pp.

1–8). Ghent, Belgium. https://doi.org/10.1109/ANIMMA.2011.6172914

184. Becker, P. C., Olsson, N. A., & Simpson, J. R. (1999). Erbium-doped fiber amplifiers: Fundamentals and

technology. Academic Press.

185. Udalcovs, A., et al. (2022). Bibliometric trends of optical amplifier research: SOAs vs. EDFAs. Journal

of Optical Communications and Networking, 14(12), 1031–1045. https://doi.org/10.1364/JOCN.471005