The polarizer is used to transmit a particular polarization state and cut off the rest. When the polarizer is at a Brewster Angle to the incident light, the film can enhance the reflectivity of the S – polarized light while maintaining the high transmittance of the P – polarized light. The front surface of the polarizer is coated with high reflective layer (HR) and ordinary reflective film (R). The reflectivity of HR film to S – polarized light is up to 99.5%, while the reflectivity of R film to P – polarized light is lower than 2%, and the polarization effect is strong.