Patent ID: 8351783

Claim:
A chromatic dispersion measuring apparatus comprising: a pump light source for emitting pump light with a wavelength λ pump , the wavelength λ pump being tuned; a probe light source for emitting probe light with a wavelength λ probe , the wavelength λ probe being tuned under the condition where the wavelength λ probe is apart from the wavelength λ pump by a given wavelength or a given frequency; a measuring means for measuring the 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; and an analysis tool for calculating the chromatic dispersion of the device by detecting pump light wavelengths for making a generation efficiency of the idler light local extreme values in the relationship between the pump light wavelength and the generation efficiency of the idler light, and then by calculating phase mismatch among such detected pump light wavelengths, the corresponding probe light wavelengths, and the corresponding idler light wavelengths.