A light emitter and a bias control method for an optical modulator

The present invention provides a method for controlling the light emitter and the optical modulator bias method. The optical transmitter comprising: a signal generator configured to generate data based on input driving signal; an optical modulator configured to intensity of light having an output voltage in response to the applied voltage is changed - light intensity characteristics and is configured to generate the drive signal corresponding to an optical signal; multiplier, which is configured with the drive signal from the electric signal obtained by multiplying the optical signal; and a control unit, which is configured to controlling the bias voltage of the optical modulator based on an output of the multiplier.