Patent ID: 7138156

Claim:
Within a method of making an optical interference filter having thin layers of alternatingly high and low indices of refraction, a method of determining layer thicknesses, said method comprising the steps of: (a) providing sample spectra and measurements of a predetermined characteristic associated with respective said sample spectra; (b) selecting an initial number of said layers; (c) selecting a thickness for each layer of said number of layers; (d) determining a transmission spectrum of an optical filter having said number of layers and said selected thickness of each said layer; (e) defining a first regression formula that relates an interaction of light with said transmission spectrum to a regression value; (f) applying each said sample spectrum to said regression formula, thereby determining said regression value for each said sample spectrum; (g) defining a comparison relationship that compares said regression values and said measurements; and (h) optimizing said comparison relationship for said regression values based upon minimization of differences between said regression values and said measurements, wherein thickness of each said layer is an optimization variable.