Oscillation polarization mode selective semiconductor laser, light transmitter and optical communication system using the laser.

摘要

An oscillation polarization mode selective semiconductor laser for selectively performing one of oscillations in different polarization modes, is provided. The semiconductor laser includes a substrate, a laser structure formed on the substrate, and a phase shift region formed in the laser structure. The laser structure includes an active region in which population inversion is established by a current injection thereinto. At least a portion of the phase shift region has a strained quantum well structure in which degrees of a change in refractive index for internal light in different polarization modes due to a current injection thereinto are different from each other. The polarization mode of a light output from the laser can be changed by a small amount of current injected into the phase shift region, and fluctuation in the output intensity can be suppressed during a transition operation in polarization mode.