RayJackONE - Birefringence

A circularly polarized light source illuminates a quarter-wave plate, which converts the polarization state into linear #polarization. After the light has passed through a uniaxial crystal, two images are visible on the screen, caused by the ordinary and extraordinary rays, respectively. The relative brightness of both images depends on the polarization direction of the light that is incident on the crystal - which can be controlled by rotating the quarter-wave plate.