Research of Thin Film for Laser Polarization Beam Splitter

Based on the design theory of film stack,H4 and SiO2 were selected as the high and low refractive index materials respectively. Through optimization by Macleod and TFCalc software, plus considering the internal electric field intensity distribution of film and laser induced damage threshold as well,the beam-splitting film with Tp=65±5% and Ts=30±5% in the 600-700 band in condition of 45 °± 3 ° incident angle has been achieved. Adopting electron beam ion assisted deposition system to development, the deposition parameters of materials has been optimized via orthogonal matrix experiment. The fabrication of thin film for laser polarization beam splitter has been succeeded. Its optical properties, mechanical properties and resistance to environmental test of the film have been approved to meet all using requirements.