Patent ID: 6614511
Filing Date: 2003-09-02
Classification: G01J,G01M

Abstract:
A light wavelength dispersion measuring apparatus comprising:a short pulse light generator adapted to generate short pulse light; an optical coupler to branch the short pulse light from the generator to provide a pulse light to a device under test and a reference pulse light; a first photoelectric conversion unit adapted to receive measured pulse light outputted from the device under test and adapted to execute photoelectric conversion of the measured pulse light to output a measured pulse signal; a second photoelectric conversion unit adapted to execute photoelectric conversion of the reference pulse light to output a reference pulse signal; a first band-pass filter adapted to extract a first frequency signal having a frequency component from the measured pulse signal; a second band-pass filter adapted to extract a second frequency signal having the same frequency component as that of the first frequency signal from the reference pulse signal; a phase comparison unit adapted to detect a phase difference between the first frequency signal and the second frequency signal to output a phase difference signal; and a wavelength dispersion calculation unit adapted to measure a group delay amount based on the phase difference signal to calculate a wavelength dispersion value.