Damage-resistant thin-film plate polarizer

A thin-film plate polarizer with a high polarization ratio for single laser wavelengths can be realized if a Fabry-Perot filter design is used. The spectral with of the polarization region of the filter polarizer is smaller than that of the usual long-wave pass filter, but there are not the practical difficulties of depositing multilayer systems with a large number of layers having non-quarter-wave thicknesses. Experimental results of the Fabry-Perot filter polarizer at 355 nm with HfO2 and SiO2 are presented. The laser-induced damage thresholds of the polarizer are enraised by both minimizing locally high light intensities and minimizing absorption.