Electric field absorption light modulation driving apparatus and method having improved feature to eliminate noise from optical output

摘要

An electric field absorption light modulation unit includes a light emission device for emitting light and a modulation device for varying a light transmittance thereof of light applied by the light emission device so as to provide the light as a result of modifying thereof. A driving signal generating unit coupled with the electric field absorption light modulation unit generates a driving signal to be applied to the modulation device from an input information signal by making the modulation device vary the light transmittance thereof, and the driving signal generating unit provides the driving signal so that the driving signal in a fluctuation range in which an undesirable level fluctuation may be present, corresponds to a constant working range of the modulation device, the light transmittance thereof staying at a constant value in the constant working range.