Semiconductor laser element, method of fabrication thereof, and multi-wavelength monolithic semiconductor laser device

Abstract

The present invention provides a semiconductor laser element, a method of fabrication thereof, and a multi-wavelength monolithic semiconductor laser device that achieve self-sustained pulsation up to a high output level and achieve self-sustained pulsation over a wide output range. A semiconductor laser element that exhibits self-sustained pulsation in a predetermined output region, said semiconductor laser element comprising: a substrate; a first conductive type clad layer formed on said substrate; an active layer formed on said first conductive type clad layer for emitting light by current injection; a second conductive type first clad layer formed on said active layer; and a stripe-shaped second conductive type second clad layer formed on said second conductive type first clad layer in a first direction, in such a manner that the cross-sectional surface of said stripe-shaped second conductive type second clad layer in a direction perpendicular to said first direction has a shape having an upper edge and a lower edge that face each other and side edges that connect between said upper edge and said lower edge, where the minimum width thereof is at least 70% but no more than 100% of the maximum width.