Patent ID: 6573985
Filing Date: 2003-06-03
Classification: G01M

Abstract:
A wavelength dispersion measuring device, comprising:a modulating unit modulating a light output from a light source; a transmitting unit transmitting the modulated light to a transmission line as a wavelength dispersion measurement light; a light receiving unit receiving the modulated light which propagates through the transmission line; a filter unit extracting a sideband signal from the received modulated light; and a phase difference detecting unit detecting a phase difference between different frequency band components of the sideband signal, wherein a wavelength dispersion value of the transmission line is calculated from the phase difference, and wherein said light receiving unit comprises a local oscillation light generating unit generating a local oscillation light having a predetermined frequency, and an optical multiplexing unit multiplexing the local oscillation light with the modulated light; and said light receiving unit performs heterodyne detection for the modulated light.