Optical EngineeringInfrared reflection polarizers using uniform and Gaussian low-index layers buried in high-index substrates
|Format||Member Price||Non-Member Price|
The extinction ratio (ER) and the throughput or reflectance for the unextinguished s polarization (Rs ) are calculated for infrared reflection polarizers that consist of a low-index transparent layer embedded in a high-index transparent substrate. The dependence of ER and Rs on the depth and width of the buried layer is illustrated by iso-ER and iso-Rs contours for a specific SiO2-in-Si IR reflection polarizer that operates at 3.5-?m wavelength and 80-deg angle of incidence. The two cases of a uniform layer with sharp boundaries and a diffuse Gaussian layer are considered. The diffuse-layer model employs Bruggeman’s effectivemedium theory and is intended to simulate devices that are fabricated by the oxygen-ion implantation of Si. The effect of an outermost oxide film and the angular and wavelength sensitivities of these polarizers are determined.