Reflective semiconductor optical amplifiers (RSOAs) are versatile gain media that find applications in passive optical networks. Due to their double-pass characteristics, they show better gain compared with ordinary semiconductor optical amplifiers, resulting in better switching performance. In this work, the RSOA-based gain dynamics is utilized to design and analyze a parity checker and generator using soliton pulses. The results of MATLAB simulations at a rate of 200 Gbps show the practical feasibility of such gates. The effect of the amplified spontaneous emission noise on the performance of the logic gate is also investigated.

Numerical simulations of an all-optical parity generator and checker utilizing a reflective semiconductor optical amplifier at 200 Gbps

All optical frequency encoded logic gates XOR and XNOR are designed and simulated using quantum dot semiconductor optical amplifiers (QDSOA) at 1 Tb/s for the first time as far as our knowledge goes. The logic gates use Mach Zehnder Interferometer (MZI) configuration. Simulation of gain and phase dynamics of QDSOA is presented. The present paper investigates output bit patterns using MATLAB. Amplitude Modulation (AM) is calculated and found to be as low as 0.007 dB for unsaturated gain of 10 dB of the QDSOA. A maximum Quality factor 27 dB is calculated for 5mW control power. The paper also investigates the effect of QDSOA length on quality factor. In this paper, I have modified the definitions of AM and Quality Factor (Qfe) to apply in case of frequency encoded logic.

Design and analysis of all optical frequency encoded X-OR and X-NOR gate using quantum dot semiconductor optical amplifier-Mach Zehnder Interferometer

In this paper, the unique features of the reflective semiconductor optical amplifiers (RSOAs) are exploited to numerically simulate the ultrafast performance of an all-optical NOT-AND (NAND) logic ...

120 Gb/s all-optical NAND logic gate using reflective semiconductor optical amplifiers

In this communication, a new semiconductor optical amplifier (SOA)-based module for multi-valued logic units using the cross-polarization modulation effect is proposed and analyzed. The design is simple and compact, consisting of only three SOAs and a few passive optical elements. SOAs have very low switching power (< 1mW), and are very small (< 1 mm) and integrable into modern optical integrated circuits. Being multifunctional, the design is versatile; it can function as a demultiplexer, comparator, half adder, half subtractor, and as basic (OR, AND), universal (NOR, NAND), XOR, and XNOR logic gates. This design follows a tree architecture, operates at very high speed (~ 100Gbit/s), and provides a good Q factor (30 dB or more). The corresponding bit error rate (BER) is very low (~ 10–24). In this work, a relative eye opening as large as 90.4% is calculated. The variations in Q and BER with noise and control power are also investigated.

Design analysis and applications of all-optical multifunctional logic using a semiconductor optical amplifier-based polarization rotation switch

The continuous quest for reversible computation that could be extensively used in applications such as digital signal processing, quantum computing, quantum-dot cellular automata, and nanotechnology has recently discovered its optical implementation as light tenders high-speed computing with the slightest information loss. The electro-optic effect of a lithium-niobate-based Mach-Zehnder interferometer is explored to configure a 4×4 modified Fredkin gate, capable of furnishing as many as 16 logical combinations, and thus showing potential of curbing the area overhead. The optical design is carried out using the beam propagation method. We have also performed the mathematical modeling and analyzed the results in MATLAB.

Optical configuration of modified Fredkin gate using lithium-niobate-based Mach–Zehnder interferometer

All-optical frequency-encoded AND, OR, and NOT logic gates are proposed and their performance simulated to confirm their feasibility. Terahertz optical asymmetric demultiplexer (TOAD)-based logic gates with a control pulse energy as low as 50 fJ are used, and real-time simulations of their input and output pulse patterns reveal a rate of 20 Gbps. Such logic gates could be used for future all-optical logic processors for optical computation and communication systems.

An alternative method for implementation of frequency-encoded logic gates using a terahertz optical asymmetric demultiplexer (TOAD)

Hybrid encoding technique for the representation of the binary states of information, four-wave mixing in semiconductor optical amplifier (SOA) as frequency generator and cross-polarization rotation effect in semiconductor optical amplifier as a frequency converter are used to design all-optical universal logic gate NAND. The devices can perform ultrafast operation and easily integrable. The simulated results of the proposed logic gate ensure feasibility of the proposals.

All-optical logic gate NAND using semiconductor optical amplifiers with simulation

Design and performance of all optical ternary NOT & XOR gate using the Dual semiconductor optical amplifier (SOA)-based technology is investigated. The basic principal behind the operation of these logic gates is nonlinear cross-polarization modulation (XPolM) effect in SOA. Optical NOT gate is universal logic gate, and optical XOR gates are very useful in designing higher order optical devices like flip-flops, parity checker and generator circuits, etc. The Q-value of the design is greater than 50 dB maintaining high operational speed (~ 100Gbit/s) ensures negligible bit error rate. Numerical simulation using MATLAB ensures CR values more than 55 dB and ER values more than 50 dB. These high values ensure practical feasibility of the proposed devices. The large relative eye opening(> 94%) ensures clear transmissions of the information.

Ashif Raja

Papers

An alternative method for implementation of frequency-encoded logic gates using a terahertz optical asymmetric demultiplexer (TOAD)

Numerical simulations of an all-optical parity generator and checker utilizing a reflective semiconductor optical amplifier at 200 Gbps

All-optical logic gate NAND using semiconductor optical amplifiers with simulation

Design analysis and applications of all-optical multifunctional logic using a semiconductor optical amplifier-based polarization rotation switch

Analysis of new all optical polarization-encoded Dual SOA-based ternary NOT & XOR gate with simulation