Design and analysis of Tbps all-optical gray code converter using photonic crystal-semiconductor optical amplifier-Mach–Zehnder interferometric structure

Abstract

Future communication networks require the entire communication system to be all-optical to overcome the bandwidth constraints of electronics. All-optical devices play a vital role in supporting future networks, which demand a high speed of up to Tbps. An all-optical gray code converter operation was demonstrated numerically using a photonic crystal semiconductor optical amplifier (PhC-SOA) in a Mach-Zehnder interferometric (MZI) configuration at 1 Tbps for M-ary differential phase shift keying modulated binary and BCD inputs. The design achieved a very high extinction ratio of about 123.8 dB with a good quality factor value of about 45. The results show that PhC-SOA-based XOR and OR gates in the gray code converter design exhibits improved modulation features compared with traditional SOAs in our previous works.

All optical Majority gate using Quantum dot SOA based Tera hertz Optical Asymmetric Demultiplexer (TOAD)

“…In all optical logic processing still there are many unsolved challenges [2]. All optical logic implementations includes simple logic operations like OR, NOT, XOR etc [3], half adder [4], full adder [5], comparator [6], flip-flops [7], parity generator-checker [8], code converters [9], programmable logic array [10], canonical logic unit(CLU) [2] etc. Among these CLU and PLA together is very effective for implementation of different complex logic processors for high speed optical processing.…”

“…A variant of SOA is quantum dot SOA (QDSOA) has advantages compared to bulk SOA in terms of gain recovery time and shows faster switching speed [22,23] compared to its bulk counterpart. Interferometric structures using SOA and QDSOA like tera hertz optical asymmetric de-multiplexer (TOAD) [6], Mach-Zehnder interferometers (MZI) are also very important devices for logic device implementation [24] due to their high operating speed, low power requirement and higher switching window. Quantum dot SOA based TOAD (QDSTOAD) is therefore an important switching element having advantages of QDSOA and TOAD for the implementation of different logic gates and processors.…”