Patent ID: 8488229

Claim:
A method for calibration of an optically variable filter array apparatus having a wavelength selection element including a multiplicity of pixels two-dimensionally arranged in a lattice pattern on an xy plane as a light-receiving surface, for effecting filtering by allowing incidence of at least a single wavelength-dispersion light beam which is dispersed according to wavelength on said wavelength selection element, with an x-axis direction defined as a wavelength dispersion direction, and then varying light passage characteristics by controlling a voltage to be applied to each of the pixels, the method comprising the steps of: inputting wavelength-scanned light of single spectrum into said optically variable filter array apparatus to detect a correlation between an x coordinate of said wavelength selection element and a wavelength of incident light, and putting resultant data in storage; and inputting wavelength-scanned light of single spectrum into said optically variable filter array apparatus and varying a voltage to be applied to each of the pixels of said wavelength selection element to measure a relationship between an applied voltage and an insertion loss for each of wavelengths of light which is incident on and exits from said wavelength selection element, and putting resultant data in storage, said detection of the correlation between the x coordinate of said wavelength selection element and the wavelength of incident light comprising the steps of: putting a plurality of pixel groups in the form of lines into a passage state in a direction perpendicular to the wavelength dispersion direction in said wavelength selection element; scanning wavelength on a wavelength variable light source for producing output of single-spectrum light within a wavelength range including wavelengths with which the optically variable filter array apparatus can be controlled for an input of wavelength-scanned light; and establishing of correlation in a manner such that, when an output corresponding to a line in a passage state of said wavelength selection element is produced from said optically variable filter array apparatus, on the basis of a wavelength of incident light found at the time of emission and the coordinates of a pixel in a passage state, the wavelength is correlated with the x coordinate of the wavelength selection element.