Electro optical modulation system

摘要

An electro optical modulation system utilizes electro optical effect of a crystal. The electro optical modulation system comprises a voltage comparator for comparing a modulated light intensity signal with a reference voltage; and a bias controlling device which feeds a differential signal between mean value signal of the output of the voltage comparator and mean value signal of the inverted output of the voltage comparator, to an optical modulator as a bias voltage.