Patent ID: 6445478
Filing Date: 2002-09-03
Classification: G01J,G02F,H04J

Abstract:
An optical pulse generating apparatus comprising:a light source for outputting an optical signal with a determined wavelength; an oscillator for outputting an electric clock signal with a determined frequency; a first optical modulator connected to the oscillator for modulating a power of the optical signal with the electric clock signal and outputting a first modulated optical signal; a second optical modulator for modulating a power of the first modulated optical signal outputted from the first optical modulator with the electric clock signal and outputting a second modulated optical signal; an optical multiplexer for receiving one of the first modulated optical signal inputted to the second optical modulator and the second modulated optical signal outputted from the second optical modulator, outputting a part of a multiplexed optical signal and branching a part of the multiplexed optical signal; a photo detector for converting the multiplexed optical signal from the optical multiplexer to an electric signal; a phase changing unit for changing a phase of an optical signal; and a controlling circuit for receiving the electric signal outputted from the photo detector and the electric clock signal outputted from the oscillator, and controlling a phase change amount of the phase changing unit to match a phase of the electric signal and a phase of the electric clock signal.