Birefringent Crystal

We are using birefringent crystals to split our beam of light into s and p polarized states. S and P come from German words for parallel and perpendicular. The light passes through one crystal, which transmits only one polarization state on towards the camera and sends the other one through a second crystal, which then reflects the polarized light onto the other half of the camera. The result are mirrored images, like this! 

These aren't nanorods at all. Its just dust and marker on a glass slide. But it is easier to see how these images line up than the nanorods, which just look like little speckles. The crystals are held in place with a 3D printed frame. If they aren't aligned correctly, the two images can overlap instead of having a nice clear divide down the middle. That would compromise our measurements, so I'll work on checking out consistent those crystals are later.