Patent ID: 8395762

Claim:
A chromatic dispersion measuring apparatus comprising: a pump light source for emitting pump light with a wavelength λ pump ; a probe light source for emitting probe light with a wavelength λ probe ; a measuring means for measuring a power of idler light having a wavelength λ idler output from a device under test according to four-wave mixing generated by propagation of the pump light and the probe light through the device under test; and an analysis tool for calculating the chromatic dispersion of the device at a specific wavelength λpump on the basis of results obtained by seeking a generation efficiency of idler light relative to the wavelength λ probe when the pump light having a specific wavelength is propagated and by detecting a frequency difference or wavelength difference between the pump light and the probe light that makes an extremum of generation efficiency of the idler light and by calculating a phase mismatch among the pump light wavelength having such frequency difference or wavelength difference, the corresponding probe light wavelength, and the corresponding idler light wavelength in the device under test.