Distributed feedback semiconductor laser with monitor.

摘要

A distributed feedback semiconductor laser with monitor, in which the energy gap of a light absorbing layer (16,(17)) provided on the window region (31) alone is smaller than the energy gap of the light emitting layer (3) and in which an independent pn-junction isolated from the pn-junction in the laser region is provided in or at one edge of the light absorbing layer (16, (17)) on the window region (31).