Optical semiconductor device, driving method therefore, its use as a light source and optical communication system using the same

摘要

An optical semiconductor device, such as an optical flter and an oscillation polarization selective semiconductor device for switching oscillation polarization modes between two different polarization modes, includes at least one gain region, at least one lossy region, a first control unit (108a, 108b, 109; 208a, 208b, 209; 308a, 309; 513, 514) for controlling the gain region to control a gain spectrum of the device, and a second control unit (108c, 109; 208c, 209; 308b, 309; 513, 514) for controlling the lossy region to control a cavity loss spectrum of the device such that a polarization dependency with respect to the two different polarization modes is imparted to the cavity loss spectrum. The gain region includes a light waveguide with an active layer (104a, 204a, 304a, 504a) which allows the two different polarization modes. The lossy region includes a light waveguide which allows the two different polarization modes.