Patent ID: 7324181

Claim:
A non-absorbing polarization color filter comprising the following elements: a rear broadband multilayer lossless polarizer having a predefined-oriented transmission axis AB; a front broadband multilayer lossless polarizer having a front surface and a rear surface facing the rear broadband multilayer lossless polarizer, located approximately in parallel with the rear broadband multilayer lossless polarizer, and having a transmission axis approximately parallel or approximately orthogonal with respect to transmission axis AB; a color polarization rotator located between the front broadband multilayer lossless polarizer and the rear broadband multilayer lossless polarizer approximately in parallel with said polarizers and comprising a stack of thin birefringent films with c-axes orientations alternated in sign according to a rocking angle α with respect to orientation of the transmission axis AB, wherein a number, a rocking angle α, thicknesses and optical anisotropies of thin birefringent films are selected so, that the non-absorbing polarization color filter transmits a predetermined color light having the polarization state approximately parallel to transmission axis AB, reflects said predetermined color light having the polarization state orthogonal to the transmission axis AB, and reflects an unpolarized light of other predetermined color.