The optical bistability of polarisation in B5NH4 crystal caused by the optical Kerr effect

Abstract We present experimental results concerning the polarisation optical bistability in the B 5 NH 4 crystal together with an attempt of its theoretical explanation based on third-order optical nonlinearity and Fresnel's boundary conditions. In our experiments a strong laser beam is transmitted through a crystal plate of B 5 NH 4 . The polarisation state of the transmitted light depends in a bistable way on the intensity of the incident light.