Basically I have to combine two separate broadband (445nm-650nm) beams of light, then separate them again. When separated they have to be the same polarization.
I think the easiest solution is linearly polariing one of the beams, using a reflective wire polarizer to combine the beams, then on the other end another reflective wire grid polarizer to separate the beams but have a half wave plate for one to make both beams the same polarization.
Will a half waveplate switch the polarization state of a linearly polarized broadband beam of light?
And if yes, do such half waveplates come in very thin or film forms?
Longer description:
I want two video projections to go through the same lens, then be split apart again on the other side of the lens. Since both are in the same wavelength range only way I see them sharing the same lens is having a different polarization. On the other side I'd want both of them to be the same polarization after being split again. If I have them different polarization when going into the lens on the other side I can't easily get both the same polarization anymore as using a simple absorbtive polarization filter will filter one out completly. Only solution I see is having one image polarized, the other unpolarized and using that to split the two after the lens with a reflecive polarizer and then waveplate for one of the beams.