Semiconductor Optical Amplifier Mach-Zehnder Interferometer Research Articles

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.

Concurrent M-QAM transmission performance assessment in a combined four SOA-MZIs arrangement

In this paper, the utilization of four semiconductor optical amplifier Mach-Zehnder interferometers (SOA-MZIs) is explored to achieve concurrent M-QAM (M-ary Quadrature Amplitude Modulation) transmission. Utilizing an actively mode-locked laser, we generate pulses with a duration of 0.5 ps at a repetition rate of 20 GHz, serving as our sampling source. The incoming M-QAM signals, spanning various frequencies, undergo down-mixing at the SOA-MZIs combined exit, resulting in diverse output frequencies by respecting the bandpass sampling procedures. The unparalleled simultaneous M-QAM transmission is assessed through critical metrics such as error vector magnitude (EVM) and bit error rate (BER). The SOA-MZI conversion efficiency (CE) exhibits a notable transition, ranging from 90 % at 76 GHz to 68 % at 84 GHz based on 1024-QAM data. The concurrent down-mixed signals showcase EVM values of 3, 2, 1, and 0.25 % for 16-, 64-, 256-, and 1024-QAM, respectively, at the first range of output frequencies. Besides, an exceptional BER value of 93×10−6 is attained at a symbol rate of 0.25 GSymb/s at 84 GHz for the 1024-QAM replica. A comparative analysis reveals that under identical parameter settings, the proposed Gaussian filter expounds lower EVM values compared to the root raised cosine (RRC) filter. These results highlight the success of the novel experimental approach employing SOA-MZIs for simultaneous down-mixing of four M-QAM carriers with varying levels, showcasing outstanding performance outcomes.

Terahertz Replica Generation of Ultra-High Data Rate Transmission in an Electro-Optical Semiconductor Optical Amplifier Mach–Zehnder Interferometer System

This article presents an analysis of an electro-optical up-converter relying on a semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI). The pulsed control signal is generated by an optical pulse clock (OPC) with a repetition rate of fs= 19.5 GHz. The intermediate frequency (IF) signal, which carries the modulation format known as quadratic phase shift keying (QPSK) at a frequency fIF, is shifted at the output of the SOA-MZI to high outlet mixing frequencies nfs±fIF, where n represents the harmonic order of the OPC. To examine the characteristics of the sampled QPSK signals, we employ the Virtual Photonics Inc. (VPI) emulator and evaluate them using significate metrics like error vector magnitudes (EVMs), conversion gains, and bit error rates (BERs). The up-mixing process is mainly achieved through the cross-phase modulation (XPM) effect in the SOA-MZI, which operates within a 195.5 GHz ultrahigh frequency (UHF). The electro-optical SOA-MZI up-converter demonstrates consistent uplifting conversion gains across the scope of the output mixing frequencies. The simulated conversion gain deteriorates from 38 dB at 20 GHz to 13 dB at 195.5 GHz. The operational efficiency of the electro-optical SOA-MZI design, employing the standard modulation approach, is also evaluated by measuring the EVM values. The EVM attains a 24% performance level at a data rate of 5 Gbit/s in conjunction with the UHF of 195.5 GHz. To corroborate our results, we compare them with real-world experiments conducted with the UHF of 59 GHz. The maximum frequency range of 1 THz is attained by increasing the OPC repetition rate. Ultimately, through elevating the control frequency to 100 GHz, the generation of terahertz replicas of the 4096-QAM (quadrature amplitude modulation) compound signal becomes achievable at heightened UHF, extending 1 THz, while maintaining a data transmission rate of 120 Gbit/s and upholding exceptional performance characteristics.

Performance amelioration of simultaneous up- and down-mixing contingent on a parallel SOA-MZIs design

The primary focus of this research is the creation of a first-ever experimental investigation for simultaneous up-down mixing based on three parallel semiconductor optical amplifier Mach-Zehnder interferometers (SOA-MZIs). The three mixed signals from the SOA-MZI terminals are coupled together to create a simultaneous up or down-mixed signal using an optical coupler (OC). The identified mixing function makes use of the consequences of cross-gain modulation (XGM) as well as cross-phase modulation (XPM) that have been shown at the SOA-MZI outlets. Furthermore, the performance characterization of the photonic parallel system is examined and assessed in the optical and electrical sectors. The outcomes of our experiment closely resemble those of the simulation. Several measurable factors, including power scaling measurements, optical conversion gain (OCG), power stability, beam quality factor, electrical conversion gain (ECG), and error vector magnitude (EVM), are employed to evaluate the photonic up and down-mixed signals. This three-parallel SOA-MZIs architecture has a wide range of applications involving radio over fiber and optical telecommunications. A 256-QAM (Quadrature Amplitude Modulation) up- and down-mixed signals can have a top bit rate of 64 Gbit/s with excellent EVM values. Additionally, the maximal frequency range of the concurrent up and down-mixed signal is 80 GHz. The ECG also displays significant values for up and down conversion. In the optical domain, the OCG has the highest values of 15 dB for the up-mixed signal and 12 dB for the down-mixed one, with a data input power of −10 dBm. Finally, the simultaneous mixing system tackles an outstanding beam quality factor with M2 measurement of less than 1.3 (M2<1.3).

SOA-MZI Differential Transformation Approach Applied on Simultaneous Electro-Optical Mixing

We experimentally incubate a ground-breaking design, for the first time, of concurrent electro-optical semiconductor optical amplifier Mach–Zehnder interferometer mixing (SOA-MZI) based on a differential transformation methodology. Projecting the simultaneous electro-optical mixing system and improving its efficiency and quality achievement in optical and electrical features is a crucial task due to the characteristics of an optical pulse source (OPS) operating with a repetition rate of f= 58.5 GHz and a pulse width duration of 1 picosecond (ps). The resultant of the contemporaneous electro-optical mixing exhibits exceptional passive power stability, reaching 0.8% RMS over a two-hour period. Furthermore, when the optical bandpass filter is controlled at the data wavelength of 1540 nm, we achieve up to 30 dBm of the overall mean output power with an optical conversion gain of 46 dB and an exceptionally high optical signal-to-noise ratio reaching 80 dB. Using orthogonal frequency division multiplexing (OFDM) signals, each data subcarrier is modulated using 128 quadratic amplitude modulation (128-QAM) at carrier frequencies fk and simultaneously up-mixed to high aim frequencies nf±fk at the SOA-MZI output. Additionally, the resulting OFDM_128-QAM up-mixed signal is examined using the specifications for the error vector magnitudes (EVMs) and the electrical conversion gains (ECGs). The SOA-MZI mixing experiment can handle high frequencies up to 120 GHz. Positive ECGs are followed by a sharp reduction over the entire band of the aim frequencies. The highest frequency range achieved during the realistic investigation is shown at 2f+f4= 120 GHz, where the EVM reaches 8% with a symbol rate of 15 GSymb/s. Furthermore, the concurrent OFDM_128-QAM up-mixed signal achieves an absolute maximum bit rate of 80.4 Gbit/s. The investigation into the simultaneous electro-optical mixing regime is finally supported by unmatched characterization improvements.

Establishment of an Electro-Optical Mixing Design on a Photonic SOA-MZI Using a Differential Modulation Arrangement.

We design and evaluate two experimental systems for a single and simultaneous electro-optical semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) mixing system based on the differential modulation mode. These systems and the optimization of their optical and electrical performance largely depend on characteristics of an optical pulse source (OPS), operating at a frequency of f= 39 GHz and a pulse width of 1 ps. The passive power stability of the electro-optical mixing output over one hour is better than 0.3% RMS (root mean square), which is excellent. Additionally, we generate up to 22 dBm of the total average output power with an optical conversion gain of 32 dB, while achieving a record output optical signal to noise ratio (OSNR) up to 77 dB. On the other hand, at the SOA-MZI output, the 128 quadratic amplitude modulation (128-QAM) signal at an intermediate frequency (IF), f1, is up-mixed to higher output frequencies nf ± f1. The advantages of the resulting 128-QAM mixed signal during electrical conversion gains (ECGs) and error vector magnitudes (EVMs) are also evaluated. The performed empirical SOA-MZI mixing can operate up to 118.5 GHz in its high-frequency range. The positive and almost constant conversion gains are achieved. Indeed, the obtained conversion gain values are very close across the entire range of output frequencies. The largest frequency range achieved during experimental work is 118.5 GHz, where the EVM achieves 6% at a symbol rate of 10 GSymb/s. Moreover, the peak data rate of the 128-QAM up mixed signal can reach 70 GBit/s. Finally, the study of the simultaneous electro-optical mixing system is accepted with unmatched performance improvement.

All-Optical Three-Input “AND” Gate Dependent on a Differential Modulation Architecture

This gazette focuses on simulation and experimental studies for all-optical three-input “AND” gate schemes. The proposed gate exploits the semiconductor optical amplifier Mach-Zehnder Interferometer (SOA-MZI) nonlinearities, particularly the cross-phase modulation (XPM) corollary in addition to the cross-gain modulation (XGM) corollary, which originates from a SOA-MZI differential modulation concept. Further, the system performance is analyzed and examined through actual and simulated results to evaluate the obtained “AND” gate signal. Dependent on the nonlinearity of SOAs, the all-optical “AND” gate can operate with three signals driven by a 2 picoseconds (ps) optical pulse source (OPS). We noticed that our experimental results are perfectly matched to the simulated results. The output “AND” signal is acquired at higher common harmonics up to 200 GHz in the simulation study and the optical “AND”, which can vastly be used in optical networking, is evaluated through many parameters, such as error vector magnitude (EVM), extinction ratio (ER), and gain. As a result, the pinnacle bit rate for the 16-QAM (Quadrature Amplitude Modulation) and 256-QAM “AND” signal reaches 100 and 200 Gbit/s, respectively, at the 100 GHz common harmonic frequency.

16-Bit (4 × 4) Optical Random Access Memory (RAM) Bank

During the past years, the limited access-times and memory bandwidth in electronic random-access memory (RAM) has triggered a concerted research effort towards deploying optical memory circuitry for exploiting the inherent high-bandwidth characteristics of light-based technologies. Yet the deployment of optical memory elements in functional optical RAM demonstrations has still been limited to single-bit capacity levels, with the few multi-bit demonstrations still offering only storage functionality without any true random-access capabilities. In this article, we demonstrate an experimental 16-bit all-optical RAM bank prototype that follows a 4 × 4 matrix organization and supports addressable random access storage of four 4-bit WDM-formatted optical Data Words at a 20 Gb/s memory-throughput. The proposed architecture constitutes of completely passive Row/Column decoding (RD/CD) subsystems, four Semiconductor Optical Amplifier Mach-Zehnder Interferometer (SOA-MZI) Access Gates (AGs) for enabling the access towards the 4 available Word Lines (WLs) and 16 all-optical Flip-Flops (AOFF) arranged in a 4 × 4 RAM bank. Each FF is incorporated in an indicative photonic integrated circuit (PIC). The experimental validation of the complete 16-bit RAM bank reveals error-free operation in Write mode with a peak power penalty between 8.3–10.2 dB at 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−9</sup> bit-error-rate (BER) measurements, indicating a roadmap for two-dimensional addressable (2D) RAM banks that can penetrate the optical computing application domain.

Sampling Parallel SOA-MZIs Configuration for All-Optical Simultaneous Frequency Down-Conversion

In this paper, we expound a modulation concept to contrive simultaneous frequency down-conversion based on a three parallel Semiconductor Optical Amplifier Mach-Zehnder Interferometers (SOA-MZIs) link by using a band pass sampling method in a Virtual Photonics Inc. simulator. Each SOA-MZI is deployed to achieve a down-converted signal, which has ten replicas related to the first ten harmonic ranks of the sampling signal, at the SOA-MZI outer port. Then, the admixture of the three down-converted signals yields a sampled signal, which is called a simultaneous down-converted signal that contains thirty different replicas. The positive down-conversion gains with top values are reached with the sampling parallel SOA-MZIs link. Moreover, we evaluated the quality of the parallel SOA-MZIs transmission system over orthogonal frequency division multiplexing (OFDM) complex modulated signals using the error vector magnitude values as a performance index. The utmost bit rate attained is 2 Gbit/s for OFDM modulations.

Frequency Alteration Built on an Electro-Optical Sampling SOA–MZI Using a Differential Modulation Schema

In this paper, we present a real and simulated study of a frequency up mixing employing an electro-optical sampling semiconductor optical amplifier Mach–Zehnder interferometer (SOA–MZI) along with the differential modulation schema. The sampling signal is generated by an optical pulse clock (OPC) at a frequency of fs= 19.5 GHz. The quadratic phase shift keying (QPSK) signal at an intermediate frequency (IF) fIF is shifted to high frequencies nfs ± fIF at the SOA–MZI output. Using a simulator entitled Virtual Photonics Inc. (VPI), we generate sampled QPSK signals and analyze their merits during conversion gains and error vector magnitudes (EVMs). We conducted simulations of mixing in the SOA–MZI operating in a high-frequency band up to 195.5 GHz. The positive conversion gain is accomplished over the mixing frequencies. The EVM is used to evaluate the performance of the electro-optical sampling up-convertor. The EVM reaches 14% at a data rate of 5 Gbit/s at 195.5 GHz. During the experimental work, the results obtained in simulations are set side by side with the factual ones in the frequency range up to 59 GHz. Thus, the comparison between them confirms that they have approximately the same performance.

Simultaneous Up-Conversion Based on a Co- &amp; Counter-Directions SOA-MZI Sampling Mixer with Standard &amp; Differential Modulation Modes

Simulation and experimental performance analyses of simultaneous up-converted signals, for the first time, were investigated utilizing a semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI) sampling mixer in co- and counter-directions for standard and differential modulation modes. An optical pulse source at a sampling frequency of fs = 15.6 GHz was used as a sampling signal. The IF signal channels carrying quadrature phase shift keying (QPSK) data at frequencies fm were up-converted at different mixing frequencies up to 195.5 GHz. Using the Virtual Photonics Inc. (VPI) simulator, we realized mixed QPSK signals and studied their characteristics through a conversion gain and an error vector magnitude (EVM). Simulations of up mixing operated in a frequency range up to 158 GHz. For the standard modulation in the co-direction, the conversion gain decreased from 43.3 dB at the mixing frequency of 16.6 GHz to 21.8 dB at 157 GHz for the first channel and from 43 dB at 17.6 GHz to 21 dB at 158 GHz for the second channel. The use of the differential modulation principle improved the conversion gain by about 10 dB at 195.5 GHz compared to standard modulations in co- and counter-directions. The EVM reached, respectively, 15.5 and 17.5% for the differential modulation in both configurations, at the bit rate of 100 Gbit/s at 195.5 GHz. The benefit provided by the differential modulation was that EVM values were shifted by 20% for all channels in both configurations at 100 Gbit/s. In the real measurement, we confirmed that co-directional conversion exhibited a better performance than the counter-directional operation. In addition, the real mixed signal exhibited lower efficiency and quality in comparison with simulated signals due to the sensitivity of the receiver.

Optical RAM Row With 20 Gb/s Optical Word Read/Write

During the past years, optical memories have emerged as the main way to enable fast access times and increased memory bandwidth in synergy with optical interconnections. The migration, however, to fully functional and practical optical RAMs and cache memories will require an additional yet essential step: Optical memories have to get organized into an optical memory subsystem for delivering seamless cooperation between storage and peripheral decoding units, exploiting also the wavelength dimension for efficient RAM architectural layouts. In this paper we demonstrate the first experimentally verified Wavelength Division Multiplexing (WDM) -enabled optical RAM Row subsystem comprising both the peripheral decoding circuitry and a 4-bit optical RAM Row for storing 20Gb/s 4-bit WDM-formatted optical data words. The proposed scheme comprises a single shared multi-λ Semiconductor Optical Amplifier Mach-Zehnder Interferometer (SOA-MZI) Access Gate (AG) for granting access-control to the complete RAM Row, a passive Column Decoder (CD) that directs the incoming WDM-formatted data words to the respective RAM cells that are in turn based on four broadband Indium Phosphide (InP) photonic integrated Flip-Flops (FFs). Our experimental verification firstly investigates the broadband capability of the elementary InP monolithic RAM cell at 5 Gb/s, revealing error-free Write functionality with <4.5 dB power penalty across the whole C-band confirming in this way the potential of efficient scaling to multi-cell WDM-enabled RAMs. Then, experimental validation of the complete 4-bit WDM-enabled optical RAM Row with 20 Gb/s WDM-formatted data words is performed, featuring simultaneous Access gating, decoding and storage operation for all four RAM cells, having a peak power penalty within the range of [4.6-5.6] dB for Write and [2.2-2.9] dB for Read functionalities, respectively, at a Bit Error Rate of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−9</sup> .

Repetition rate performance for frequency mixing of four simultaneous QPSK signals based on a SOA-MZI photonic sampling mixer

A simultaneous frequency up conversion of four intermediate frequency (IF) signals is carried out by utilizing a semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI) in a differential configuration for radio over fiber applications. A sampling signal compelled by an optical pulse clock source produces 10-ps-width pulses at a repetition rate domain that is from 7.8 to 19.5 GHz. The four IF signals carrying quadratic phase shift keying (QPSK) data at frequencies fm are up converted at the SOA-MZI output at mixing frequencies nfsk ± fm, where k and m equal 1, 2, 3, and 4 and n is the harmonic rank of the sampling signal. The simulation study for simultaneous frequency up conversion relied on the SOA-MZI sampling mixer is developed to acquire the conversion gain and the error vector magnitude (EVM) in the repetition rate range. Using the virtual photonics integrated simulator, we show that incrementing the repetition rate from 7.8 to 19.5 GHz improves the competence and merit of the optical transmission system due to a better signal level and a lower aliased noise power with a higher sampling rate. Positive conversion gains were achieved at a higher mixing frequency for each channel. Concomitantly, the benefit on the conversion gain provided by augmenting the sampling frequency is 14 dB. By increasing the repetition rate, the EVM can be ameliorated up to 12% for all channels. In addition, it degrades more when the frequency channel increases over the repetition rate range. The maximum bit rate of 25 Gbit / s with a QPSK modulation meets the forward error correction limit.

Simultaneous up- and down-frequency mixing based on a cascaded SOA-MZIs link.

In this paper, a simultaneous frequency up- and down-conversion is performed using a cascaded semiconductor optical amplifier Mach-Zehnder interferometers (SOA-MZIs) link for radio-over-fiber (RoF) applications. The intermediate frequency (IF) signal carrying quadratic phase shift keying (QPSK) data at a frequency f1 is up-converted at the SOA-MZI1 output at nfs±f1, where n is the harmonic rank of the first sampling signal. In addition, this up-converted signal is concurrently up- and down-converted at the SOA-MZI2 output at mfs+nfs±f1 and |nfs±f1-mfs|, respectively, where m is the harmonic rank of the second sampling signal. Using the virtual photonics integrated (VPI) simulator, it has been shown that the optical transmission system based on a cascaded SOA-MZIs link has a better efficiency and more endurable quality of the frequency mixing of QPSK signals and the higher frequency range for up- and down-conversions. Positive conversion gains are obtained at the highest mixing frequency of 101.9 and 86.3 GHz for up- and down-conversions, respectively. The best error vector magnitude provided using a cascaded SOA-MZIs link is 15.5% at the mixing frequency of 101.9 GHz for up-conversion and 18% at 86.3 GHz for down-conversion at the bit rate of 40,500 Mbit/s. The maximum bit rates of 40.5, 81, and 121.5 Gbit/s for QPSK, 16-QAM, and 64-QAM modulations, respectively, that meet the forward error correction limit is fulfilled by using a cascaded SOA-MZIs link. Another advantage of using the cascaded SOA-MZIs link is the up- and down-conversion simultaneously achieved at the second stage.

OFDM signal down frequency conversion based on a SOA-MZI sampling mixer using differential modulation and switching architectures

A simulation performance analysis of a semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI) sampling mixer used as a frequency down converter is presented by employing differential modulation and switching architectures. A clock pulse signal, generating 2 ps-width pulses at a sampling frequency of 13 GHz, is used as a sampling signal. Two optical carriers, intensity-modulated by a sinusoidal signal at 79 and 80 GHz are simultaneously down converted to 1 and 2 GHz, respectively. For the differential modulation architecture, conversion gains of about 34 and 32 dB are demonstrated for the frequency down conversion to 1 and 2 GHz, respectively. Besides, the conversion gain of 20 dB is achieved for down conversion from 79 to 1 GHz for the differential switching architecture. Furthermore, signals modulated by an orthogonal frequency division multiplexing (OFDM) complex modulation format at different bit rates are also down converted from 79 to 1 GHz and from 80 to 2 GHz and their error vector magnitude (EVM) is evaluated and compared. A maximum bit rate of about 8 Gbps satisfying the forward error correction (FEC) limit is fulfilled using differential modulation and switching architectures.

SOA-MZI photonic sampler with a post-distortion linearization technique.

We present a post-distortion linearization technique for a semiconductor optical amplifier Mach-Zehnder interferometer (SOA-MZI) photonic sampler. The sampling source is an active mode-locked laser producing 12.6 ps-width pulses with a repetition frequency of 10 GHz. The mathematical model for the linearization technique is presented and then evaluated for the quasi-static regime, i.e. sampling continuous-wave signals, and for the dynamic regime, i.e. sampling sinusoidal signals. A significant improvement in terms of total harmonic distortion (THD) equal to 23.4 dB is observed for a modulation index equal to 80% in the quasi-static regime, matching the highest observed THD improvement in the dynamic regime.

Design of all-optical Johnson counter using SOA-MZI at 100 Gb/s

All-optical networks utilize optical memory elements as the basic building blocks for optical signal processing and for providing high performance computing applications. In this communication, we propose and realize an integrable scheme for the design of all optical Johnson counter utilizing D flip flops (DFFs). All optical counter have been designed using cascaded DFFs memories and a single clock pulse have been applied as input to the counter. The DFF has been implemented by employing semiconductor optical amplifier - Mach Zehnder Interferometer (SOA-MZI) based all optical NAND and NOT gates. The performance of the device has been investigated in terms of extinction ratio, Q factor, amplitude modulation and contrast ratio verifying its operation at 100 Gb/s.

All-optical ripple carry adder based on SOA-MZI configuration at 100 Gb/s

Ripple carry adders are broadly used for the addition of n-bit input sequences in arithmetic and logic units and for performing packet-header processing in all optical packet switched networks. In this paper, we have proposed the novel design of 2-bit ripple carry adder based on semi-conductor optical amplifier- Mach Zehnder Interferometer (SOA-MZI) configuration at 100Gb/s. The XOR, OR and AND gates have been employed as basic gates in the design of ripple carry adder. The four input signals of the adder circuit and the resultant outputs attained are at the same wavelength. The performance of the proposed device has been analyzed in terms of extinction ratio(ER), contrast ratio(CR), quality factor(QF) and amplitude modulation(AM) at the output.

Design and performance analysis of SOA-MZI-based Tbps all-optical gray converters with M-ary DPSK coded binary, gray, and octal inputs

We propose three different types of all-optical code converters with high data rates of 1 Tbps based on a semiconductor optical amplifier in Mach–Zehnder interferometer configuration. The gray code is a cyclic code, which is more suitable for accurate representation of numbers, error detection, correction, and rounding of decimal quantities. The OR and XOR logic gates are the key structures in the proposed design to convert binary inputs to gray (BITG), binary coded decimal (BCD) inputs to gray (BCDTG) and octal inputs to binary (OCTB) outputs. The output of proposed all-optical gray code converters is verified for all three types of input representations. The bit error rate is negligible for all the input combinations. The obtained average extinction ratio for all-optical code converters are 87, 84, and 78 dB. The optimum value of quality factor up to 59 is achieved at 0.1 A, ±5, and 0.3, respectively, for the injection current, linewidth enhancement factor, and optical confinement factor. For the first time to the authors’ knowledge, all-optical gray code converters yield high data rates of 1 Tbps for the semiconductor optical amplifier-Mach–Zehnder interferometer configurations using the M-ary differential phase-shift keying modulation scheme.

M-ary DPSK coded binary to gray, BCD to gray, and octal to binary all-optical code converters based on SOA-MZI configuration at 500 Gb/s.

Gray codes are broadly used as the cyclic codes to assist error correction in optical communications. In this paper, we have proposed the novel design of three different types of all-optical gray code converters based on the semiconductor optical amplifier (SOA) Mach-Zehnder interferometer (MZI) configuration. The XOR and OR gates are the basic devices used for the proposed design of binary to gray, binary-coded decimal (BCD) to gray, and octal to binary code converters. For the first time, to the best of the authors' knowledge, a high data rate of 500 Gbps is achieved for the three types of all-optical code converters using the SOA-MZI configuration by exploiting an M-ary differential phase shift keying (DPSK) modulation scheme. The performance factors of the proposed all-optical code converters like extinction ratio, bit error rate, and quality factor are calculated.