Broadband thin-film polarizers for high-power laser systems

We propose to construct broadband thin-film polarizers (TFPs) by combining the polarizing regions of long-wave pass and short-wave pass stacks. The polarization bandwidth can be broader than traditional TFPs by roughly a factor of 2. We designed and fabricated two HfO(2)/SiO(2) Brewster's angle TFPs with a high contrast ratio in the spectral range of 1064±25 nm. The laser-induced damage was investigated and illustrates that the two designs possess quite different laser damage properties due to the different electric field distributions. Nevertheless, broadband TFPs with high laser-induced damage threshold can be achieved with proper coating design.