Thin film polarizers are dielectric coated glass substrates designed for use at Brewsters angle. The Brewster angle design results in a relatively good polarization purity (typically 200:1) at low cost. Since the transmitted p-polarization is not reflected from the glass surface, an anti-reflection coating on the back side is not required.
These are high damage threshold, economical polarizers, typically used for Q-switching.
When using thin film polarizers, the lateral offset of the transmitted beam must be taken into account. This depends on the thickness of the substrate. Thin film polarizers function for one wavelength only.
Two polarized beams
Low Polarization Purity
Suitable for high power applications