Distributed feedback semiconductor laser with different light intensity of the locking part of a lead of the different polarization modes, as well as related control mechanism

摘要

A distributed feedback semiconductor laser includes a cavity extending in a cavity-axial direction. The cavity has a plurality of regions including a first region (110, 210, 311, 451 and 561) and a second region (111, 211, 312, 452 and 562) arranged along the cavity-axial direction and capable of being independently pumped. The laser further includes a plurality of waveguides with a diffraction grating (101a, 201a, 315, 411 and 511) and an active layer (103, 203, 303, 403 and 432) extending along the cavity-axial direction. The waveguides are formed in the regions, respectively, and coupled to each other along the cavity-axial direction. Different first and second polatization modes are defined by the coupled waveguides. The waveguides are constructed such that light intensity distributions along the cavity-axial direction in the first and second regions when pumped are different between the first and second polarization modes.