All Optical Logic Gates: A Tutorial

In this paper we describe the performances of different kinds of all-optical logic gates reported up to now. We introduce all-optical logic gates based on semiconductor optical amplifiers such as ultrahigh speed logic gates exploiting four-wave mixing, cross gain modulation, cross phase modulation, and cross polarization modulation. We demonstrate the performances of all-optical logic gates using delayed interferometers, such as all-optical gates based on Mach-Zehnder and nonlinear loop mirror interferometers. We describe the performances of semiconductor based microring resonator logic gates, such as all-optical logic gates based on nonlinear photonic crystal, couplers and waveguides, lasers and cavities. We illustrate optical gates based on electro-absorption modulator, nonlinear fibers, nanoslabs, and optical thyristor. We introduce molecular logic gates and logic gates based on thermal lens effects