Understanding Electro-optic Behavior
Pockels cell alters the polarization of a transmitted light beam when voltage is applied to the cell by causing a phase retardation between orthogonal polarization components of the beam. In the absence of an applied field, there is no difference in the phase retardation between orthogonal polarization components of the light beam because the refractive index is the same for both polarization directions and so there is no polarization change in the transmitted light.
