Autocompensation of polarization state changes - Mirror/reflector and Faraday mirror

islahna

Hi,
I read several literatures on quantum cryptography plug and play system. I found out that Faraday mirror was used to compensate polarization fluctuations. Photons are reflected orthogonally by Faraday mirror and their polarization changes will then be autocompensated, provided they follow the same path (same fiber). I'm thinking if we use a Mirror/reflector, will polarization changes be auto compensated as with Faraday Mirror ? Is it necessary that the reflected lights be orthogonally rotated in order to get autocompensated ?
thanks in advance.

regards,
--islahna