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 gatesexploiting four-wave mixing, cross gain modulation, cross phase modulation, and cross polarization modulation. wedemonstrate the performances of all-optical logic gates using delayed interferometers, such as all-optical gates basedon mach-zehnder and nonlinear loop mirror interferometers. we describe the performances of semiconductor basedmicroring resonator logic gates, such as all-optical logic gates based on nonlinear photonic crystal, couplers andwaveguides, 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