LIGHT MODULATION DEVICE AND LIGHT MODULATION METHOD

WIPO Patent Application WO/2015/156394

A1

This light modulation device detects the power of light modulated by an I component light modulation unit and a Q component light modulation unit, synchronously detects the component of a frequency (fd) from the power of the modulated light, when adjusting a first bias voltage or second bias voltage, outputs a signal of frequency (fd/n) (where n is a positive integer that is 1 or greater) as a dithering signal added to the first bias voltage or second bias voltage, when adjusting a third bias voltage, outputs two mutually orthogonal signals of frequency (fd/m) (where m is a positive integer that is 1 or greater and n