Polarization independent thin film optical interference filters

摘要

Design and construction of polarization-independent thin film interference filters is accomplished by applying at least one of the following design rules to an original filter design including quarter wave stacks (QWS) of layers of alternating higher index material (H) and lower index material (L) and half wave cavities (HWC): design rule 1-increasing or decreasing the thicknesses of HWC's in the filter by a small (less than ¼ wavelength) increment; design rule 2-adding small increments (less than ¼ wavelength) to one or more layers and correspondingly subtracting equivalent aggregate increments from one or more adjacent or nearby layers; or design rule 3-replacing HWC's with asymmetric composite HWC's.