Generation of quasi-steady and steady state PR solitons in an optically active crystal

Spatial solitons in photorefractive crystals are of great interest because they represent a well describable model scheme for solitons in other materials. In our presentation, we show that we have succeeded in generating stable self-focused states in an optically active crystal with a lifetime of several hours. Depending on external parameters quasi-steady 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 behaviour of the spatial soliton and the self-focusing strength can be adjusted by the ratio of the intensities of the signal and the background beams, respectively, and by the externally applied electric field.