# How a TFP (Thin Flim Polarizer) works?

Hello.

I've been really curious about how TFP (Thin Flim Polarizer) works. I've searched TFP information through the Internet which tells that TFP utilizes Brewster's angle. This explains how the P-polarization transmits TFP with 100 % transmission, but I don't know how the S-polarization is filtered out as a high reflection. A Multi-layer dielectric coating on TFP substrate for a high reflection could be a solution, but...it could mean both P and S-polarizations are highly reflected at a TFP surface.

If the coating is precisely designed (in terms of refractive indices of coating materials and coating layer thicknesses) such that the P-polarization goes through every surfaces of coating layers and the TFP substrate at Brewster's angle, then the S-polarization is highly reflected while the P-polarization gets 100 % transmission. This is my TFP design principle, but...I'm not sure if this is a usual way of the TFP design.

Could you give me any feedback of this question?