Optical signal processing using semiconductor laser amplifiers

SLAs can be used in the linear, nonlinear or optoelectronic mode of operation. The combination of these different operation conditions provides various optical functional devices: all-optical regenerators, fibre dispersion compensators, all-optical frequency converters, switching gates, modulators, detectors and tunable active filters. Consequently the SLA turns out to be a very general device for optical signal processing, comparable to the transistor in electronics. The authors describe some of these functional devices, and discuss the advantages and disadvantages of the SLA as functional element for optical signal processing.