PHASE MODULATION DEVICE, TRANSMISSION DEVICE, RECEPTION DEVICE, AND PHASE MODULATION METHOD

摘要

A phase modulation device which realize high-precision high-speed phase modulation of a dual light pulse. A phase modulator (105) provided in the phase modulation device phase-modulates a dual light pulse in proportion to the applied voltage of an electrical pulse when the dual light pulse with the time difference between a signal light pulse (SP) and a reference light pulse (RP) passes through it. Consequently, the phase-modulated pulses (SP', RP') are outputted. A modulating signal generator (106) outputs an electrical pulse with a predetermined bias at the input timing of a trigger signal in response to, for example, an input of a data signal having four levels. The modulating signal generator (106) outputs a dual electrical pulse composed of two pulses which have a time difference and whose polarities are opposite to each other when one trigger signal is inputted. The time difference between the two pulses of the dual electrical pulse corresponds to the time difference of the dual light pulse passing through the phase modulator (105).