Semiconductor laser with internal reflectors and vertical output

摘要

A heterostructure semiconductor laser emitting light in a direction vertical to the horizontal active layer has one or more internal reflectors for feedback. Angled reflectors, in the form of grooves etched at an angle exceeding the angle of total internal reflection through the layers, totally internally reflect light out of the laser. One or more of the following feedback constructions are used separately or in combination to provide low threshold current and frequency selection. Insulating windows may be put on the grooves. A periodic grating on a layer adjacent the active layer provides distributed feedback. A plurality of thin dielectric layers placed next to the active layer reflect light back into the active layer. Two parallel integral feedback facets crossing vertically through the active layer act as planar mirrors.