Semiconductor laser with an active layer having varying thicknesses

摘要

A semiconductor laser includes a semiconductor substrate of first conductivity type having a ridge extending in a direction substantially parallel to the direction of the light guide only in the neighborhood of the resonator end surface; a lower cladding layer of first conductivity type, an active layer, and an upper cladding layer of second conductivity type produced one after the other on the substrate in the above-mentioned order in such a manner that the portion of the active layer above the ridge is thinner than the portion of the active layer that is inside the laser resonator removed from the resonator and surface.