Patent ID: 8786950

Claim:
A method for imparting an optical filter with rugate optical characteristics, comprising the steps of: providing a bank of high index layers and low index layers, wherein each high index layer within the bank adjoins two low index layers and has an optical thickness of approximately one fourth of a wavelength of processed light, and wherein each low index layer within the bank adjoins two high index layers and has an optical thickness of approximately one fourth of the wavelength of the processed light, within each of the low index layers within the bank, providing a first plurality of high index transition layers oriented towards a first adjoining high index layer and a second plurality of high index transition layers oriented towards a second adjoining high index layer; and within each of the high index layers within the bank, providing a first plurality of low index transition layers oriented towards a first adjoining low index layer and a second plurality of low index transition layers oriented towards a second adjoining low index layer.