OPTICAL TRANSMITTER, OPTICAL TRANSMISSION METHOD, AND OPTICAL TRANSMISSION PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide an optical transmitter capable of reducing an influence of a nonlinear effect of an optical fiber, inhibiting a band required for a device from being spread, and flexibly changing over multiple modulation methods owing to easy bias control of the modulator.SOLUTION: A optical transmitter 301 includes: a modulator 101 and a controller 102. The modulator 101 is a modulator capable of applying four phase deviation modulation to light from a light source and outputting it. The controller 102 controls an input signal to the modulator 101 and operates the modulator 101 in four phase deviation modulation or &pgr;/2 shift two phase deviation modulation.