OBSERVATION OF SELF-TRAPPING OF LIGHT IN A SELF-WRITTEN CHANNEL IN A PHOTOSENSITIVE GLASS

We report the observation of self-trapping of light in a self-written channel in a photosensitive glass waveguide. As the refractive index c hanges induced in the glass are permanent, the resulting channel is al so permanent. We show that the evolution of this structure agrees well with theoretical predictions. This will allow us to confirm experimen tally predicted phenomena such as beam interaction and self-similar ev olution of the refractive index and the intensity.