Optical computation is the most desirable technology that enhances the speed, data transmission rate and processing power by replacing the electronics with the optical switches. Optical switching is efficiently performed in high speed signal processing by all optical gates. This paper reviews the progressive development of the optical switching technology, highlights the different technologies of all optical gates and other switching circuits in all optical processing. Basic gates and other logic circuits in optical computing based on nonlinear regimes using semiconductor optical amplifier (SOA), fiber and photonic crystals are discussed, compared and the challenges along with future direction is outlined. © 2018, The Optical Society of India.