Method of driving a polarization mode selective semiconductor laser with a wide modulation band, and an optical communication system

摘要

A distributed feedback laser selectively performs one of two oscillations in different polarization modes, TE or TM. Two modulation currents are injected into different electrodes of the semiconductor laser having a plurality of electrodes. The relationship between the phases of the two modulation currents is so adjusted that an output waveform is not distorted especially when a modulation frequency is low. Polarization modulation is applied as the modulation form.