Reflective Semiconductor Optical Amplifier Research Articles

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.

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.

Multi-frequency self-injection locking of a FSR-tunable multimode laser diode.

This study presents the controllable multi-frequency self-injection locking regimes realization with an original experimental setup composed of a reflective semiconductor optical amplifier, an external feedback mirror, and a high-Q chip-scale Si3N4 ring microresonator. Our findings demonstrate the conditions of multiple modes' simultaneous locking being analogous to Vernier effect. We varied the free spectral range of the external-cavity laser by its length tuning, enabling the robust generations from 1 to 4 self-injection locked narrow lines on demand, that is important for optical telecommunications, and photonic-based microwave and THz sources.

Performance-enhanced time-delayed photonic reservoir computing system using a reflective semiconductor optical amplifier.

We propose a time-delayed photonic reservoir computing (RC) architecture utilizing a reflective semiconductor optical amplifier (RSOA) as an active mirror. The performance of the proposed RC structure is investigated by two benchmark tasks, namely the Santa Fe time-series prediction task and the nonlinear channel equalization task. The simulation results show that both the prediction and equalization performance of the proposed system are significantly improved with the contribution of RSOA, with respect to the traditional RC system using a mirror. By increasing the drive current of the RSOA, the greater nonlinearity of the RSOA gain saturation is achieved, as such the prediction and equalization performance are enhanced. It is also shown that the proposed RC architecture shows a wider consistency interval and superior robustness than the traditional RC structure for most of the measured parameters such as coupling strength, injection strength, and frequency detuning. This work provides a performance-enhanced time-delayed RC structure by making use of the nonlinear transformation of the RSOA feedback.

RoFnet – Reconfigurable Radio over Fiber Network Architecture Overview

This paper introduces the basic operational concepts of the RoFnet – reconfigurable radio over fiber network, which is a project supported by the Portuguese Foundation forScience and Technology. This project proposes an innovative radio over fiber optical access network architecture, which combines a low cost base station (BS) design, incorporating reflective semiconductor optical amplifiers, with fiber dispersion mitigation provided by optical single sideband modulation techniques. Optical wavelength division multiplexing (WDM) techniques are used to simplify the access network architecture allowing for different BSs to be fed by a common fiber. Different wavelength channels can be allocated to different BSs depending on user requirements. Additionally, in order to improve radio coverage within a cell, it is considered a sectorized antenna interface. The combination of subcarrier multiplexing with WDM, further simplifies the network architecture, by using a specific wavelength channel to feed an individual BS and different subcarriers to drive the individual antenna sectors within the BS.

Dibit-based OR and NOR gates using reflective semiconductor optical amplifier

In the all-optical domain, the reflective semiconductor optical amplifier (RSOA) creates due attention in the research community because the RSOA has high gain, low-power consumption, high-speed signal processing ability as well as low noise performance. In this work, we have proposed dibit-based OR and NOR gates using RSOA. Dibit-based logic is utilized in this design to get the reduced bit-error problems and high degree of parallelism. To verify the functionality of the aforementioned designs, we have used MATLAB software and also the quality factor (Q), extinction ratio (ER), contrast ratio (CR), and bit-error-rate (BER) have been calculated.

Switchable Ultra-Wideband All-Optical Quantum Dot Reflective Semiconductor Optical Amplifier.

A comprehensive study has been conducted on ultra-broadband optically pumped quantum dot (QD) reflective semiconductor optical amplifiers (QD-RSOAs). Furthermore, little work has been done on broadband QD-RSOAs with an optical pump. About 1 μm optical bandwidth, spanning 800 nm up to 1800 nm, is supported for the suggested device by superimposing nine groups of QDs. It has been shown that the device can be engineered to amplify a selected window or a group of desired windows. Moreover, the operation of the device has been thoroughly investigated by solving the coupled differential rate and signal propagation equations. A numerical algorithm has been suggested to solve these equations. As far as we are concerned, a broadband optically pumped QD-RSOA that can operate as a filter has been introduced.

A Bidirectional WDM-PON Free Space Optical (FSO) System for Fronthaul 5 G C-RAN Networks

High-speed cellular technologies require low-latency and high-capacity optical networks. The Centralized Radio Access Network (C-RAN) architecture offers a cost-effective solution for mobile network deployment. To maximize flexibility and minimize deployment costs of fronthaul networks, we propose a hybrid bidirectional fronthaul C-RAN topology based on Wavelength Division Multiplexing (WDM) passive optical networks (PONs) and free space optical communication (FSO). The wavelength reuse scheme utilized here relies on reflective semiconductor optical amplifiers (RSOAs) to reduce cost and increase capacity. The system was demonstrated for 20 Gbps 16 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$-$</tex-math></inline-formula> quadrature amplitude modulation (16-QAM) intensity-modulated orthogonal frequency-division multiplexing (OFDM) downstream signals and 5 Gbps On-off keying (OOK) upstream signals, respectively. A Gamma-Gamma channel model is used to demonstrate optical signal transmission over an FSO link. The bit error rate (BER) results indicate that the hybrid WDM-PON-FSO based fronthaul architecture could achieve 320 Gbps over 20 km of single-mode fiber (SMF) and 700 m free space transmission.

Simulative analysis of all-optical reflective semiconductor optical amplifier based 2-to-4 line decoder and read only memory (ROM)

Abstract In this paper, all-optical 2-to-4 line decoder and read-only memory (ROM) are analyzed using a Reflective Semiconductor Optical Amplifier (RSOA) based optical switch. The structures of these 2-to-4 line decoder and read only memory are very simple and the operating speed is 200 Gbps, which can be used in optical hardware systems. The 2-to-4 line decoder output shows a very high extension ratio (ER), contrast ratio (CR), and Q value. These high values indicate the distinguishment between two states (‘1’ and ‘0’) very clearly.

Bidirectional Passive Optical Network Employing Different Line codings/Modulation Formats in Wavelength Reused RSOA Based Symmetrical 10 Gbps

Passive optical networks (PONs) with the integration of multiple channels are the high capacity systems to cater the large number of channels in order to fulfill demands of internet applications. To realize a crosstalk suppressed and cost effective system, an integrated multi channel PON for mitigation of the crosstalk between upstream and downstream channels using different pulse shapes such as Return to zero (RZ), non RZ (NRZ), compressed spectrum RZ (CSRZ), Differential phase shift keying (DPSK) is proposed. Use of reflective semiconductor optical amplifier (RSOA) has been proposed for upstream modulation to make system cost efficient. 2-channel downstream and 2-channel upstream wavelengths are used to exhibits total symmetrical data rate of 10 Gbps. Results revealed that proposed system can support 10 Gbps data rate up to 20 km

A novel approach of developing all-optical frequency encoded dibit-based Peres gate using reflective semiconductor optical amplifier

In recent trends, digital systems in the light of power dissipation are a crucial issue. In computing, the computational process of reversible logic is bijective and can decrease the rising issue of power dissipation. In reversible circuit design, Peres gate considered as one of the fundamental reversible gate. Therefore, a Peres gate using Add/Drop Multiplexer (ADM) and Reflective Semiconductor Optical Amplifier (RSOA) is proposed in this paper. Frequency encoding scheme and dibit-based logic are incorporated here. In long range transmission, frequency encoding bears huge benefits in respect with the other encoding techniques. This encoding technique may decrease the probability of bit error. Due to the high gain and low noise property of RSOA, the proposed design can perform operations like computation, data processing, etc. at ultra-high speed with low noise. MATLAB Simulink (R2018a) software has been used to verify the operation of the proposed design.

Temperature response of all-optical XOR logic function based on different semiconductor optical amplifiers

A critical area of research is studying the performance of semiconductor optical amplifiers (SOAs) at high temperatures. In this paper, the performance of all-optical exclusive-OR (XOR) logic gate is investigated at high operating temperatures (TOP) using different SOAs technologies such as conventional SOAs, carrier reservoir (CR)-SOAs, reflective SOAs (RSOAs), and photonic crystal (PC)-SOAs, for the first time to our knowledge. The time-dependent differential equations of SOAs, CR-SOA, RSOAs, and PC-SOAs at different operating data rates have been solved. The performance of the XOR logic gate is evaluated by calculating the quality factors and plotting the eye diagrams for each amplifier. Besides, the dependence of the key operating parameters on the TOP is examined and assessed for each scheme. The results showed that the RSOAs perform better at high temperatures than other proposed SOA technologies.

Quantum Dot Reflective Semiconductor Optical Amplifiers: Optical Pumping Compared with Electrical Pumping.

A comprehensive study has been conducted on quantum dot reflective semiconductor optical amplifiers (QD-RSOAs) with optical pumps (OPs). Moreover, few studies have been completed on OP-based QD-RSOAs. A comparison is made between them and QD-RSOAs with electrical pumps (EPs) in this study. It is shown that the dynamical properties of the device can significantly develop in the optical pumping version. The optical properties are studied for both methods. Moreover, by solving the coupled differential rate and signal propagation equations, the operation of the device in the pulse mode is investigated. Finally, it is proven that OP QD-RSOAs can perform significantly better in applications such as fast all-optical signal processing and wavelength division multiplexing in passive optical networks.

Hybrid integrated external cavity laser with a 172-nm tuning range

Chip-scale lasers with a wide tunable range and a narrow linewidth have rich applications in optical communications, sensing, and light detection and ranging systems. External cavity lasers (ECLs) have the advantage of a wide tuning range and a narrow linewidth compared with their counterparts such as distributed feedback lasers and distributed Bragg reflector lasers because the passive filter separated from the gain section can be widely tuned and the low-loss external cavity extends the photon lifetime. However, so far, the tuning range achieved by the chip-scale ECLs is in the range of 80–120 nm, smaller than that of the bulk free-space ECL (typically &amp;gt;160 nm). The bottleneck in reaching an ultrabroad tuning range for chip-scale ECLs lies in the unsuppressed side modes of the external cavity. Here, we demonstrate a hybrid-integrated ECL consisting of a broadband III–V reflective semiconductor optical amplifier and a low-loss Si3N4 wavelength-selective reflector. A record 172-nm lasing wavelength tuning range together with a more than 40 dB side-mode suppression ratio is achieved beyond the free spectral range of the Vernier ring filter due to the enhanced lasing mode selection from a tunable Sagnac loop reflector. The Si3N4 platform enables a low-loss external cavity, facilitating laser linewidth reduction below 4 kHz over the full tuning range. The on-chip output power reaches 26.7 mW at a wavelength of 1550 nm.

Selective band amplification in ultra-broadband superimposed quantum dot reflective semiconductor optical amplifiers.

In this paper, an approach is proposed for an ultra-broadband quantum dot (QD) reflective semiconductor optical amplifier using superimposed QDs with switching and band selection capability in the supported band. Furthermore, about 1 µm optical bandwidth is covered (O, E, S, C, and L bands), which is the desired region in most optical communication applications. Three optical windows are selected for optimized amplification (1.55 µm, 1.5 µm, 1.31 µm). Also, they can be amplified either simultaneously or one at a time, which guarantees independent modulation. This is a remarkable property in fast data transmission. The amplifier is devised by solution process nanotechnology, which guarantees its synthesizing feasibility with low cost. Finally, by introducing this amplifier, one step is taken toward the development of fast wavelength division multiplexing passive optical networks.

All-optical dibit-based Feynman gate using reflective semiconductor optical amplifier with frequency encoding scheme

All-optical dibit-based Feynman gate using reflective semiconductor optical amplifier with frequency encoding scheme

OOK-RSOA Modülasyonunu Kullanan Çift Yönlü Karma Optik IM/DD OFDM WDM-PON Sisteminin Performansının İncelenmesi

In this paper, we have studied and simulated bidirectional hybrid long reach Intensity Modulated and Direct Detected Optical Orthogonal Frequency Division Multiplexing Wavelength Division Multiplexing Passive Optical Network (IM/DD-OFDM-WDM-PON) with 100 Gbps of various M-Quadrature Amplitude Modulation (M-QAM) in transmitted downstream signal and 2.5 Gbps On-Off keying (OOK) upstream signal using wavelength reused technique by Reflective Semiconductor Optical Amplifier (RSOA) at Optical Network Unit (ONU). The simple, low cost and colorless long-haul IM/DD-OFDM-WDM-PON based on RSOA is designed to support extreme data rate signal by utilizing Dispersion Compensating Fiber (DCF). All results prove that IM/DD-OFDM-WDM-PON can achieve good Bit Error Rate (BER) performance over propagation length of (300 km for 4-QAM), (200 km for 16-QAM) and (50 km for 64-QAM). For comparison, the performance of the network is studied in terms of BER, the effect of the propagation length on the constellation diagram, and the relation of BER versus bit energy and noise density ratio (Eb/No).

Mitigation of scintillation in FSO communication using a temporally and spatially incoherent spectrum-sliced light source.

We propose and demonstrate a temporally and spatially incoherent spectrum-sliced light source for scintillation mitigation in free-space optical (FSO) communications. For the temporal incoherence, we utilize the spectrum-sliced incoherent light (SSIL) modulated by gain-saturated reflective semiconductor optical amplifiers for data modulation and the suppression of excess intensity noise inherent in a narrowband incoherent light source. We then employ offset launching from a single-mode fiber to a multi-mode fiber to add the spatial incoherence to the SSIL source. The experimental demonstration shows that this temporally and spatially incoherent light is effective in mitigating scintillation. For example, this light source reduces the transmitter power required to achieve a bit-error ratio of 10-3 by ∼6 dB in comparison with the laser source. This is an ∼3 dB larger reduction in the transmitter power than the reduction achieved by a temporally incoherent light source.

On Optically Modulated Reflective Semiconductor Optical Amplifier Pattern-Dependent Overshoot Mitigation Using a Birefringent Fiber Loop

Reflective semiconductor optical amplifiers (RSOAs) are key elements for modern optical communications. Despite their widespread deployment, their performance when intended for ultrafast data amplification is limited by their inherently slow gain dynamics. In this paper, we propose to employ a birefringent fiber loop (BFL) to compensate for the RSOA pattern-dependent behavior and extend its operation well beyond that allowed by its nominal optical modulation bandwidth. We apply a reduced model to describe the RSOA response and quantify the RSOA output distortion by means of a non-return-to-zero data pulse overshoot. We validate the outcomes of this model in the time domain both for the RSOA alone and with the assistance of the BFL by an extensive comparison to available measurements. The excellent matching between simulation and experimental results allows us to further investigate the impact of critical operating parameters and derive specifications for them so that the performance of the scheme against the overshoot is made acceptable. The theoretical predictions confirm the ability of the BFL to enhance the RSOA direct amplification capability and hence establish it as a frequency discriminator for complementing RSOAs’ versatile and scalable operation.

Damping of relaxation oscillations, photon-photon resonance, and tolerance to external optical feedback of III-V/SiN hybrid lasers with a dispersive narrow band mirror.

We address the stability of a tunable hybrid laser based on a III-V Reflective Semiconductor Optical Amplifier (RSOA) edge-coupled with a Silicon Photonic (SiPh) dispersive mirror through a model of time-delayed algebraic differential equations that accounts for the narrow band mirror. Our results allow to (i) analyze the stability of single mode lasing, (ii) quantify the impact of the mirror bandwidth on the damping of the laser relaxation oscillations and the emergence of photon-photon resonance, and (iii) study the tolerance of the laser to the external optical feedback. Thanks to this analysis, we find a mirror design that gives ultra-high stability up to an external feedback level of -10 dB. The aim of the work is providing a tool for understanding and interpreting the dynamics of these lasers and design configurations for isolator-free operation.