Consistent experimental and numerical simulation studies of the propagation of a one-dimensional Gaussian beam in optically active BSO crystal in the presence of an alternating external field are presented. We have observed three forms of the beam evolution: (i) polarization-dependent self-bending, in which the crystal acts as a nonlinear polarization beam splitter; (ii) spatially nonuniform self-modulation of the state of polarization; (iii) formation of narrow inclined waveguides within the Gaussian beam. The effects of optical activity and the crystal orientation are discussed.

• Received 10 November 1998

DOI:https://doi.org/10.1103/PhysRevLett.83.1143