Ridge type semiconductor laser of distributed feedback

摘要

A semiconductor laser includes an active layer made of semiconductor; a ridge stripe having a cladding layer formed on the active layer and a contact layer formed on the cladding layer to protrude from the active layer; a pair of gratings each having a periodic structure in a longitudinal direction of the ridge stripe having a plurality of grooves each extending from side walls of the ridge stripe on flat portions in both sides of the ridge stripe; and absorbing layers covering the surfaces of the grooves of gratings to absorb excited light.