MULTILAYER STACK WITH OVERLAPPING HARMONICS FOR WIDE VISIBLE-INFRARED COVERAGE

摘要

A broadband mirror, polarizer, or other reflector includes at least one stack of microlayers. Microlayers in the stack are arranged into optical repeat units. At a design angle of incidence such as normal incidence, the stack provides a 1st order reflection band, a 2nd order reflection band, and optionally a 3rd order reflection band. The 2nd order reflection band overlaps, or substantially overlaps, the 1st and/or 3rd order reflection bands to form a single wide reflection band. The wide reflection band may include the 2nd and 1st but not a 3rd order reflection band, or the 2nd and 3rd but not the 1st order reflection band, or it may include the 1st, 2nd, and 3rd order reflection bands, as well as still higher order reflection bands. The wide reflection band may cover at least a portion of visible and infrared wavelengths.