SEMICONDUCTOR LASER, SEMICONDUCTOR OPTICAL AMPLIFIER, AND OPTICAL COMMUNICATION APPARATUS

摘要

A semiconductor laser exhibiting excellent low power consumption characteristics and high optical output characteristics, a semiconductor optical amplifier, and an optical communication apparatus mounting them. A semiconductor laser (100) comprises an active waveguide consisting of a first waveguide (11a) providing a plurality of modes including a fundamental mode, and a second waveguide (12a) providing a multimode which is wider than the first waveguide (11a), and provides the fundamental mode as oscillation light oscillated from the active waveguide.