We present experimental results on generating stable self-focused states in an optically active PR crystal (BTO) with a lifetime of several hours. Depending on external parameters, quasi-steady state solitons can also be observed where the beam diameter undergoes a transient and symmetric self-focusing and then relaxes to an asymmetric steady state. The temporal dynamics and the strength of the self-focusing effect can be adjusted by the ratio of the intensities of the signal and the background beams, respectively, and by the applied electric field. The stability of the self-focused structures depends crucially on the absolute value of the background intensity and the specific signal intensity range. Choosing the appropriate polarization of the signal beam the disturbing effects of the optical activity can be avoided.
© 2005 Optical Society of AmericaPDF Article