OPTICAL FILTER DEVICE AND METHOD FOR DESIGNING OPTICAL FILTER DEVICE

摘要

PROBLEM TO BE SOLVED: To accurately design an optical filter device having the aimed loss wavelength characteristics by an easy method. SOLUTION: When an optical filter device is designed by assembling a plurality of optical parts having periodical loss wavelength characteristics against wavelength, the loss wavelength characteristics of the optical filter is approximated from the theoretical formula including the phase determining parameter mj (j is an integer increasing from 1 by one increment) and the amplitude determining parameter bj of the loss wavelength characteristics of each optical part to obtain all combinations of different phase determining parameters mj from a plurality of different groups preliminarily selected and to perform nonlinear fitting. Thus, a first optimum solution of each phase determining parameter is obtained, and a group of a plurality of different numbers is determined in the range near the first optimum solution and all combinations with different phase determining parameters are determined from the group of numbers to perform nonlinear fitting. Thus, optimum solutions are successively obtained and each parameter is determined to approximate the aimed loss wavelength characteristics (a).