SIMULATION OF NOT-, AND- AND OR- OPTICAL GATES USING WIDEBAND TRAVELLING WAVE SEMICONDUCTOR OPTICAL AMPLIFIER

Abstract

All optical gates have received practical applications in the recent past. This is due to its high demand in optical communication networks in this age of Information Technology (IT). They have assisted in performance of logic functions along the network such as: building of time reversals, differentiators, integrators and multiplexers. However, challenges still do exist along the communication channels such as data delay which requires automatic switches for routing, wavelength conversion, data generation and regeneration. All optical gates have been built and demonstrated using different types of Semiconductor Optical Amplifier (SOA); Travelling wave and reflective SOA to alleviate this problem. Using Optisystem software, AND, NOT and OR Optical gates were simulated using Wideband Travelling Wave Semiconductor Operational Amplifier (WTW SOA). Their setups were simulated to ascertain working characteristics. A generated pattern of signal was modulated in Mach-Zender Modulator (MZM) with 0 dBm power, 193.1 THz Continuous Wave (CW) laser through several components and fibres. At 10 Gbits, sampled bit sequences and selected injected currents and lengths of fibres and the WTW SOA, were used. The signal was generated and delayed optically along the optical fibre for a NOT gate to be realized , while it was split into two in other gates and delayed to have two overlapped input signals into the WTW SOA. It was established that the working length and current for NOT gate was 0.001 m and 0.13 A while that of AND gate was 0.003 m and 0.0003 A. The OR gate was realized at a length of 0.0000001 m and at a current of 0.0031 A. This research shows that WTW SOA produced essential optical gates at the specified lengths and injection currents. This research, if adapted, will accelerate data propagation in communication networks since all optical gates are useful in optical communication networks as they can make automatic Optical switches, data routers, multiplexers, integrators, differentiators and other combinational optical processing systems.