Semiconductor optical amplifier-based all-optical gates for high-speed optical processing

Semiconductor optical amplifiers are useful building blocks for all optical gates as wavelength converters and OTDM demultiplexers. This paper reviews the progress from simple gates using cross-gain modulation and four-wave mixing to the integrated interferometric gates using cross-phase modulation. These gates are very efficient for high-speed signal processing and will open up interesting new areas, such as all-optical regeneration and high-speed all-optical logic functions.