HALBLEITERLASER-VORRICHTUNG.

摘要

A semiconductor laser apparatus has a semiconductor laser diode (21) for radiating a laser beam (30a), a photodetector (23) formed on a semiconductor substrate (22), a prism (24) having a first plane (24a) for introducing the laser beam (30a), for example onto an optical disc, and for introducing a reflected laser beam (30r) from the optical disc onto the photodetector (23); and a second plane (24b) facing the photodetector (23), and a coating layer (27, 28) formed on the boundary between the semiconductor substrate (22) and the prism (24). The coating layer (27, 28) has a refractive index such that laser light (30s) incident from the first plane (24a) other than the reflected laser beam (30r) is inhibited from reaching the photodetector (23).