Minimizing Search Method for Wideband Visible or Wideband Infrared Antireflection Coating Design

摘要

A design algorithm based on the minimizing search technique was proposed for designing the normal-incidence wideband visible or wideband infrared multilayer antireflection coating. The method utilized a tuning operation of the thickness of sublayers first, and then refined the antireflective performance and simplified the design by a layer minimizing operation. It was shown that the average visible spectral reflectivities of three-material thirty-layer and two-material thirty-layer minimizing search antireflection coating designs for glass substrates were reduced to less than 0.054% and 0.056% with a 12-layer structure, and the average infrared reflectivity of a two-material forty-layer minimizing search antireflection coating design for a germanium substrate over the broadband spectral region of 7.7-12.3 μm was reduced to less than 0.488% with a 22-layer structure.