English: This image is a schematic of a Pockels cell modulating the polarization of light. In this cast, the Pockels cell is acting as a quarter wave plate, where linearly polarized light is converted to circularly polarized light. With the addition of a Brewster's window (on the left) this change in polarization can be converted to a change in the intensity of the beam, by transmitting on the p-polarized vector component.