SEMICONDUCTOR LIGHT SOURCE DEVICE

摘要

A semiconductor light source device (10) comprising a semiconductor laser diode (12) and a photodiode (18). Since a pn junction is formed up to the end face, out of a plurality of end faces of the photodiode (18), in the vicinity of a region where a monitor laser light (16) emitted from at least the monitor laser light emitting face (15) of the semiconductor laser diode (12) enters, light receiving sensitivity characteristics stabilized against temperature variation are attained. Consequently, a stabilized laser output can be obtained from the semiconductor laser diode (12).