Patent ID: 7817923
Filing Date: 2010-10-19
Classification: G02F,H04B

Abstract:
1. An optical transmitting apparatus for transmitting an optical signal modulated corresponding to a data signal, comprising: a phase shifter to control a phase of at least one of a first optical signal and a second optical signal, acquired by splitting by an optical input, so that the first and the second optical signals have a predetermined phase difference on an optical waveguide; a data modulator to modulate the first and the second optical signals by using the data signal on the optical waveguide; a first generator to generate a first low-frequency signal; a second generator to generate a second low-frequency signal from the first low-frequency signal; a superimposer to superimpose the first and second low-frequency signals on the first and the second optical signals, respectively; a monitor to monitor at least one of maximum power, minimum power and phase of the low-frequency signal or a higher harmonic signal of the low-frequency signal, superimposed on a modulated optical signal acquired by coupling the first and second optical signals modulated by the data modulator; and a controller to control the phase shift unit using an output of the monitor unit by maximizing a frequency component with a same frequency as the low-frequency signal or minimizing a frequency component with a double frequency of the low-frequency signal.