Patent ID: 6570698
Filing Date: 2003-05-27
Classification: G02F,H04B

Abstract:
An apparatus for modulating an optical intensity, with amplitude noises suppressed by using a linear optical modulator, comprising:a pilot signal generating means for generating pilot signals so as to adjust a bias voltage; a phase delaying means for delaying a phase of the pilot signals after their generation by said pilot signal generating means; a linear optical modulating means for receiving the phase-delayed signals and from said phase delaying means and for receiving optical signals from an external source to linearly modulate the phase delayed signals and the optical signals; a signal adding means for adding together data signals (from an external source) and the pilot signals from said pilot signal generating means; an optical intensity modulating means for receiving negatively fed-back signals to adjust the bias voltage, and for receiving the added signals from said signal adding means and the linearly modulated signals from said linear optical modulating means to modulate the optical intensity; a photo detecting means for detecting output signals of said optical intensity modulating means to convert them to electrical signals; a frequency component amplitude measuring means for receiving the electrical signals from said photo detecting means and the pilot signal generating means to measure an amplitude of a frequency component so as to generate negatively fed-back signals and so as to transfer them to said optical intensity modulating means; and a linear optical device for receiving the phase-delayed signals from said phase delaying means and for offsetting an error inducing signal, wherein the linear optical device includes a laser diode.