Patent ID: 7418206

Claim:
A control method of a wavelength dispersion compensator which comprises: an optical component provided with a demultiplexing function, including a device having two reflective surfaces which are opposed and parallel to each other, in which a light condensed in a one-dimensional direction is incident between said reflective surfaces of the device, and a part of said incident light is transmitted through one of said reflective surfaces while said incident light being multiple-reflected on the reflective surfaces, to be emitted, and said emitted light interferes mutually, so that optical beams traveling directions of which are different from each other according to wavelengths are formed; and a reflector reflecting, at a previously set position, optical beams of respective wavelengths emitted from one of the reflective surfaces of said optical component in different directions to return the optical beams to said optical component, respectively, said control method comprising: acquiring to store data relating to wavelength dispersion values in respective wavelengths in a wavelength band of the incident light so as to correspond to a position of said reflector, before starting an operation of wavelength dispersion compensation by said wavelength dispersion compensator; inputting a setting condition inclusive of the wavelength dispersion values to be compensated at an operation time and wavelength information of the incident light; reading out the data corresponding to said setting condition from said stored data, and based on said read data, judging a position of said reflector, which enables the reduction of wavelength dependence of the wavelength dispersion values in the operation time; and controlling the position of said reflector in accordance with a judgment result, to start the operation of wavelength dispersion compensation.