Traveling-wave semiconductor laser amplifiers for optical communications systems

Abstract

Abstruct-Optical amplification is a key technology for future optical communications systems. The latest state of the art for semiconductor laser amplifiers (SLAs) is reviewed, as well as future possibilities for SLAs. Design criteria for improving SLA characteristics are clarified from the viewpoint of both material gain parameters and amplifier operating conditions. The most essential amplifier characteristics for the communications system application are high saturation power and small noise figure, which are achieved by traveling-wave semiconductor laser amplifiers (TWAs). In order to fabricate TWAs, anti-reflection (AR) coating, angled facet structures and window facet structures have been studied to reduce facet reflection.