Semiconductor Optical Amplifier Research Articles

Semiconductor Optical Amplifiers with Wide Gain Bandwidth and Enhanced Polarization Insensitivity Based on Tensile-Strained Quantum Wells

Semiconductor Optical Amplifiers with Wide Gain Bandwidth and Enhanced Polarization Insensitivity Based on Tensile-Strained Quantum Wells

Fully spectrum-sliced four-wave mixing wavelength conversion in a Semiconductor Optical Amplifier

Fully spectrum-sliced four-wave mixing wavelength conversion in a Semiconductor Optical Amplifier

Enhanced ultra-wideband optical frequency comb generation based on cross-polarization modulation effect of semiconductor optical amplifier

Enhanced ultra-wideband optical frequency comb generation based on cross-polarization modulation effect of semiconductor optical amplifier

Enabling cost-effective wireless THz communication through semiconductor optical amplifier’s direct/cross gain modulation for seamless integration of hybrid fiber-coaxial connectivity

We propose a cost-effective THz wireless communication scheme for future femtocell networks that leverages either direct gain modulation (DGM) or cross gain modulation (XGM) of a semiconductor optical amplifier (SOA) to convert coaxially or optically carried data into intensity-modulated THz waves, respectively. This architecture, based on an SOA and a uni-traveling-carrier photodiode (UTC-PD), has advantages over typical THz modulation schemes involving a resonant tunneling diode or an electro-optic modulator combined with a UTC-PD. Consequently, it facilitates the seamless convergence of hybrid fiber-coaxial networks to THz radio access networks with low cost, straightforward monolithic integration, and a more compact footprint. Furthermore, we experimentally verified the possibility of non-return-to-zero on–off keying wireless communication over 0.5 meters in the 300 GHz band, achieving real-time transmission of 4 Gbit/s for coaxial access via an SOA’s DGM and 10 Gbit/s for fiber access via the SOA’s XGM. Notably, these data rates were attained by simple non-coherent THz intensity demodulation based on a Fermi-level managed barrier diode while meeting the 7% hard-decision forward error correction (HD-FEC) threshold (3.4×10−3). Finally, we conducted an analysis of the merits and drawbacks of the proposed THz communication scheme based on the combination of an SOA and a UTC-PD, discussed bottlenecks that hinder further rate improvement, and explored possibilities for optimization. In conclusion, this scheme is crucial for realizing future ultra-high-speed wireless networks that seamlessly connect to fiber-coaxial networks.

Design and Analysis of a Narrow Linewidth Laser Based on a Triple Euler Gradient Resonant Ring

We designed a narrow-linewidth external-cavity hybrid laser leveraging a silicon-on-insulator triple Euler gradient resonant ring. The laser’s outer cavity incorporates a compact, high-Q resonant ring with low loss. The straight waveguide part of the resonant ring adopts a width of 1.6 μm to ensure low loss transmission. The curved section is designed as an Euler gradient curved waveguide, which is beneficial for low loss and stable single-mode transmission. The design features an effective bending radius of only 26.35 μm, which significantly improves the compactness of the resonant ring and, in turn, reduces the overall footprint of the outer cavity chip. To bolster the laser power and cater to the varying shapes of semiconductor optical amplifier (SOA) spots, we designed a multi-tip edge coupler. Theoretical analysis indicates that this edge coupler can achieve an optical coupling efficiency of 85%. It also reveals that the edge coupler provides 3 dB vertical and horizontal alignment tolerances of 0.76 μm and 2.4 μm, respectively, for a spot with a beam waist radius of 1.98 μm × 0.99 μm. The outer cavity, designed with an Euler gradient micro-ring, can achieve a side-mode suppression ratio (SMSR) of 30 dB within a tuning range of 100 nm, with a round-trip loss of the entire cavity at 1.12 dB, and an expected theoretical laser linewidth of 300 Hz.

A Single-Longitudinal-Mode S + C Band Wavelength-Tunable Fiber Laser.

An external cavity wavelength-fiber ring laser (ECWTFL) based on a semiconductor optical amplifier and a combined wavelength scanning filter in the Littrow configuration is proposed and experimentally demonstrated. With the benefit of the combination of an external cavity wavelength filter and a Lyot filter, the laser achieves a single-mode narrow linewidth output with a linewidth of 1.75 kHz. The wavelength tuning range reaches 133 nm, covering the entire S + C band. The proposed ECWTFL is used for demodulation of a fiber EFPI sensor; the result shows that the proposed ECWTFL has the ability to demodulate the small cavity-length FPI sensor.

23 KHz linewidth 1064 nm SOA based fiber laser by using parallel type subring cavities

This study presents a high-quality fiber ring laser created by integrating a semiconductor optical amplifier to generate amplified spontaneous emission with a four-subring resonator and utilizing the nonlinear polarization rotator effect. When the driven current of 400 mA, the laser exhibited a maximum power deviation of 0.204 dB and a wavelength deviation of 0.012 nm during a one-hour testing period. Furthermore, utilizing a delayed self-heterodyne measurement system, we measured the linewidth of the self-made fiber laser to be 23 kHz.

A Time-Differential BOCDA Sensor Measurement System Applied to a 1 km Long SMF Using a Semiconductor Optical Amplifier as a Pump Chopper.

A time-differential (TD) Brillouin optical correlation domain analysis (BOCDA) sensor system was applied to measure the Brillouin gain spectrum of a 1 km long sensing optical fiber. The optical delay line used in all BOCDA measurement systems was eliminated in the TD-BOCDA system by using a bit-delayed modulation relationship between the probe and pump lightwaves. These lightwaves were phase modulated using 216-1 pseudo-random binary sequence codes at 5 Gbps. A 2 cm dispersion-shifted fiber placed at the end of the 1 km optical fiber was distinctly identified by the Brillouin frequency extracted from the Brillouin gain spectrum measurement. To investigate the measurement stability of the TD-BOCDA system, experiments were conducted under two different pumping conditions. A semiconductor optical amplifier (SOA) and an intensity modulator (MOD) were compared for the pump chopper used in the TD-BOCDA system to detect the extinction ratio of the pump and the resulting noise in the Brillouin gain measurement. The stability of the Brillouin frequency measurement from the Brillouin gain spectrum in the TD-BOCDA system was investigated by increasing the average value of the measurement using either the SOA or MOD. The repeated-measurement deviation of the system with the SOA was only half of the deviation observed in the system with the MOD. The performance of TD-BOCDA is equivalent to or better than that of conventional BOCDAs in terms of measurement reliability. Moreover, TD-BOCDA is free from the drawbacks of traditional BOCDA, which uses time-delayed fibers and varies the bit rates.

High-speed and high-precision measurement of biaxial in-plane displacements: tens of nanometers principle error suppression in microprobe sensors

When the microprobe sensor is faced with the demand of high-speed biaxial displacement measurement, due to the characteristics of phase generated carrier (PGC) technology, accompanying optical intensity modulation (AOIM) and unfavorable phase modulation depth (PMD) will bring about the tens of nanometer cyclic nonlinear errors, further hindering high-speed and high-precision measurement. Herein, a light source intensity stabilization system based on semiconductor optical amplifier (SOA) feedback control is achieved to eliminate the error caused by AOIM in the presence of high-frequency and large-amplitude laser modulation. Based on this, the reasons for large nonlinear errors in biaxial measurements and the inability to ensure the stability of the accuracy of multiple measurement axes are methodically examined, and an effective nonlinear error elimination methodology based on the normalized amplitude correction of active temperature scanning is proposed. The continuity and linearity of the temperature scanning are also discussed. The performed experiments show that the above approach is capable of reducing the displacement demodulation error from the nanometer scale to the sub-nanometer scale. Further, the nonlinear error is reduced to within 0.1 nm for both measurement axes and the performance becomes consistent. The dual-axis measurement resolution of the microprobe sensor reaches 0.4 nm and the measurement speed is better than 1.2 m/s with the standard deviation of lower than 0.5 nm.

High Efficiency O‐band Preamplified Receiver Integrated with Semiconductor Optical Amplifier and Uni‐travelling Carrier Photodiode for Passive Optical Network

With the continuous increase in data traffic and enormous consumption of data in terms of video on demand services and cloud computing, there is an increasing demand for high speed and high sensitivity short reach receivers for passive optical networks (PON) access network which are point to multi‐point networks. Avalanche photodiodes (APD) are the standard receivers in PON networks due to their high sensitivity and low cost. However, it is currently not clear if they can provide high bandwidth above 40 GHz with good performance (gain, noise, etc.). Furthermore, standard PIN photodiodes do not provide sufficient sensitivity for PON networks. Therefore, in this article a SOA‐UTC receiver is proposed, which is a photonic integrated circuit (PIC) comprising a semiconductor optical amplifier (SOA) for optical preamplification and a high‐speed uni‐travelling‐carrier (UTC) photodiode for opto‐electronic conversion. A very high responsivity of 140 A W−1 is demonstrated, with a polarization dependent loss (PDL) around 1 dB and a 3 dB bandwidth of 48 GHz, which is very promising for future PON network with 50 Gbit s−1 capacity and above.

Architecture for low-cost and highly flexible metro-access networks using SOA-based OADM nodes and digital subcarrier multiplexing with power loading.

Metro-access networks exploiting wavelength division multiplexing (WDM) to cope with the ever-growing bandwidth demands are sensitive to cost and need to be fast-configurable to meet the requirements of many new network services. Optical add-drop multiplexers (OADMs) are a key component in enabling fast dynamic wavelength allocation and optimization. In this Letter, we propose and demonstrate, to our knowledge, a novel architecture for high-performance metro-access networks that utilizes semiconductor optical amplifier (SOA)-based OADM nodes, digital subcarrier multiplexing (DSCM), low-cost direct detection receivers, and power loading techniques, which makes the designed metro-access network cost-effective, fast reconfigurable, and flexible for bandwidth allocation on demand. Through a proof-of-concept experiment, we have successfully demonstrated a prototype horseshoe optical network consisting of up to four SOA-based OADM nodes at 40 Gb/s per wavelength channel by leveraging the proposed scheme. The flexible bandwidth allocation and dynamic add and drop operations have also been achieved in an emulated WDM optical network. All results indicate the great scalability and flexibility of the proposed architecture.

A novel bidirectionally operated chirped quantum-dot based semiconductor optical amplifier using a dual ground state spectrum

Bi-directionally operated amplifiers enabling efficient utilization of transmission wavelengths are promising candidates in densely integrated photonic circuits for future cost-effective, power-efficient optical networks. Here, we demonstrate, for the first time, a broadband semiconductor optical amplifier (SOA) based on a novel chirped multilayered quantum dot (QD) structure, which is suitable for bi-directional amplification via the dual ground state (GS) emission spectrum. The fabricated QD SOA has achieved a maximum 3-dB gain bandwidth of 50 nm while retaining on-chip gain above 20 dB at both GS wavelengths. Under an optimum pumping current of 280 mA, the bi-directionally operated QD SOA has shown around 10 dB receiver sensitivity improvement in ultra-high-speed 100 Gbaud non-return-to-zero and 53.125 Gbaud four-level pulse amplitude modulation data transmission systems.

Optimization of the coupling efficiency under self-injection locking in a narrow linewidth hybrid wavelength tunable laser diode

In this study, a fiber Fabry–Perot (FFP) interferometer was connected to a hybrid wavelength-tunable laser diode consisting of a semiconductor optical amplifier chip and Si photonics chip, and spectral linewidth narrowing was achieved using the self-injection locking effect. The hybrid wavelength-tunable laser was equipped with a variable-reflectivity mirror, which allowed the optimization of κ, the coupling efficiency between the laser cavity and FFP interferometer. By optimizing κ, self-injection locking stabilized, and the linewidth was controlled between 4 and 300 kHz. This laser can be used to evaluate the linewidth required for communication systems such as digital coherent communication and the accuracy required for distance measurement.

Airy pulse dynamics in semiconductor optical amplifier with dispersive gain

We analytically as well as numerically study the Airy pulse dynamics in semiconductor optical amplifier (SOA) with dispersive gain. The frequency dependent gain of the SOA not only modifies the temporal shape of the Airy pulse but also alters the peak power of the Airy pulse. The study finds that the trajectory of the Airy pulse can be manipulated by the gain induced dispersion and the linewidth enhancement factor. Moreover, the gain dispersion introduces upchirp during the propagation that suppresses the Airy pulse acceleration in anomalous group velocity dispersion while the acceleration is pronounced when the dispersion is normal.

High efficient net gain and low noise figure based vertical cavity semiconductor optical amplifiers for wavelength division multiplexing applications

Abstract This paper has demonstrated the high efficient net gain and low noise figure based vertical cavity semiconductor light amplifiers for wavelength division multiplexing applications. Previous study on the chip reflective gain variations versus SOA current under temperature effects is clarified. We have transferred light semiconductor amplifiers for wavelength multiplexing schemes applications. Amplifier output power is demonstrated with bias current and amplifier active layer region length variations based input signal power of 3, 6.5, 10 dBm, 1550 nm wavelength and optimum amplifier confinement factor of 0.45. The amplifier output noise variations are clarified against the bias current and amplifier active layer region width variations based input signal power of 3, 6.5, 10 dBm, 1550 nm wavelength and optimum amplifier confinement factor of 0.45. The output OSNR variations are studied clearly and deeply against the bias current and amplifier active layer region length variations based input signal power of 3, 6.5, 10 dBm, 1550 nm wavelength and optimum amplifier confinement factor of 0.45. The signal loss is demonstrated versus both active layer width/length and temperature based optimum 30 % gallium core dopant ratio and 28 % arsenide cladding dopant ratio at optimum input signal power of 10 dBm, 1550 nm wavelength and optimum amplifier confinement factor of 0.45. SOA amplifier output power can be enhance with the management of both bias current and input signal power and the reduction of active amplifier length. The amplifier output noise can be enhance with the management of both bias current and input signal power and the reduction of active amplifier width. Output OSNR system can be improved with the management of both bias current and input signal power and the reduction of active amplifier length. The SOA amplifier gain can be improved with the management of both bias current and input signal power and the reduction of active amplifier length. The SOA amplifier noise figure can be improved with the management of both bias current and input signal power and the reduction of active amplifier width. The signal loss can be controlled and managed by adjusting optimum 30 % gallium core dopant ratio and 28 % arsenide cladding dopant ratio, optimum active layer/with and the presence of room temperature.

Simulation and design of dual-wavelength all-optical semiconductor optical amplifier with solution-processed quantum dots

All-optical semiconductor optical amplifiers (SOAs) present a cost-effective and highly efficient solution for long-distance WDM networks. In this study, the investigation of a dual-wavelength all-optical SOA incorporating two distinct sizes of solution-processed InAs/AlAs core/shell quantum dots (QDs), operating at 1.31 and 1.55 μm wavelengths, both simultaneously and individually, has been proposed. To comprehensively evaluate the optical performance of our proposed dual-wavelength all-optical SOA, the modified coupled rate equations governing carriers dynamics and the optical photon propagation equations have been solved numerically while taking into account both homogeneous and inhomogeneous broadening, as well as fluorescence or förster resonance energy transfer (FRET) effects. This computational approach provides valuable insights into the optical behavior of dual-wavelength all-optical SOA. In our proposed structure, cost-effective solution-based methods for implementing QDs of varying sizes offer flexibility to adjust QD size across a broad range, from as small as 0.1 nm to meet specific requirements. This adjustment is made with meticulous consideration of appropriate synthesis techniques.

High-repetition-rate femtosecond "OR" gate design in a differential SOA-MZI

In this article, an experimental investigation of a combined "OR" gate design reliant on a differential semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) is presented. The suggested "OR" gate takes advantage of the cross-gain modulation (XGM) and cross-phase modulation (XPM) effects generated at the SOA-MZI outcome. Furthermore, the optical, electrical, and temporal categories are used for testing and analyzing the system's performance. This "OR" gate technology is very useful in numerous scenarios, especially in optical networking. Numerous factors, including extinction ratio (ER), beam quality factor, and optical and electrical spectra, are used for assessing the optical "OR" gate. With a beam propagation ratio (BPR) of less than 2.4 (M2<2.4), the "OR" gate design provides superb beam quality. The successful creation of the electrical "OR" transmission exhibits about sixteen harmonics with exceptional powers and substantial ERs. The last important phase in optical communications and network connectivity is pulse compression, which can increase the optical average power while enjoying the advantages of brief pulses. In fact, pulse compression combines the intense energy of an extensive pulse with the great accuracy of an extremely short pulse. The grating-fiber compressor approach is widely used to accomplish the pulse compressions. The combined "OR" output pulse, which has undergone pulse compression, has a duration of 50 fs at a wavelength of 1530 nm.

Alternative approach to design Dibit-based XOR and XNOR gate

In this generation, high-speed communication has very demanding. In this respect, optical communication plays a crucial role in meeting the goal of high-speed communication. With the increasing demands of high-speed communication, huge data processing is also needed. Therefore, we have proposed a design of XOR and XNOR gates using five reflective semiconductor optical amplifiers (RSOA). Our proposed gates are dibit logic-based. To increase the reliability of the devise, we have incorporated this logic scheme. Here, we consider the logic state ‘0’ for the absence of pulse and logic state ‘1’ for the presence of pulse. The dibit logic ‘0 1’ and ‘1 0’ are similar as ‘0’ and ‘1’ in digtal states, respectively. To check its practical feasibility, we have simulated the proposed design in Matlabsoftware and also quality factor, contrast, and extinction ratios are calculated for this design.

10 W super-wideband ultra-low-intensity-noise single-frequency fiber laser at 1 µm.

A 10 W super-wideband ultra-low-intensity-noise single-frequency fiber laser (SFFL) at 1 µm is experimentally demonstrated, based on dual gain saturation effects from semiconductors and optical fibers, together with an analog-digital hybrid optoelectronic feedback loop. Three intensity-noise-inhibited units synergistically work, which actualizes a connection of effective bandwidth and enhancement of noise-suppressing amplitude. With the cascade action of the semiconductor optical amplifier and optical fiber amplifier, the laser power is remarkably boosted. Eventually, an SFFL with an output power of 10.8 W and a relative intensity noise (RIN) below -150 dB/Hz at the frequency range over 1 Hz is realized. More meaningfully, within the total frequency range of 10 Hz to 10 GHz exceeding 29 octaves, the RIN is controlled to below -160 dB/Hz, approaching the shot-noise limit (SNL) level. To the best of our knowledge, this is the lowest RIN result of SFFL within such an extensive frequency range, and this is the highest output power of the near-SNL super-wideband SFFL. Furthermore, a linewidth of less than 0.8 kHz, a long-term stable polarization extinction ratio of 20 dB, and an optical signal-to-noise ratio of over 60 dB are obtained simultaneously. This start-of-the-art SFFL has provided a systematic solution for high-power and low-noise light sources, which is competitive for sophisticated applications, such as free-space laser communication, space-based gravitational wave detection, and super-long-distance space coherent velocity measurement and ranging.

Heterogeneous tunable III-V-on-silicon-nitride mode-locked laser emitting wide optical spectra

We demonstrate a III-V-on-silicon-nitride mode-locked laser through the heterogeneous integration of a semiconductor optical amplifier on a passive silicon-nitride cavity using the technique of micro-transfer printing. In the initial phase of our study, we focus on optimizing the lasing wavelength to be centered at 1550 nm. This optimization is achieved by conducting experiments with 27 mode-locked lasers, each incorporating optical amplifiers featuring distinct multiple-quantum-well photoluminescence values. Subsequently we present a comprehensive study investigating the behavior of the mode-locking regime when the electrical driving parameters are varied. Specifically, we explore the impact of the gain voltage and saturable absorber current on the locking stability of a tunable mode-locked laser. By manipulating these parameters, we demonstrate the precise control of the optical spectrum across a wide range of wavelengths spanning from 1530 to 1580 nm. Furthermore, we implement an optimization approach based on a Monte Carlo analysis aimed at enhancing the mode overlap within the gain region. This adjustment enables the achievement of a laser emitting a 23-nm-wide spectrum while maintaining a defined 10 dB bandwidth for a pulse repetition rate of 3 GHz.