Optical Nonlinearities in Semiconductor Lasers and Their Applications for Functional Devices

Optical functional devices based on the nonlinearities of laser diodes (LDs) are expected to be key components in future optical communications and switching systems, because of advantages such as the existence of optical gain and low optical switching power. This paper briefly summarizes optical nonlinearities in LDs and overviews the state-of-the-art active semiconductor photonic functional devices, such as bistable LDs and filters, and their applications to optical communications and photonic switching. Possibilities for improvements in switching speed, one of the biggest remaining problems, are also discussed.