Self-Focusing in Pulsed and Continuous Regime in Photorefractive Crystals KNbO3, LiNbO3, SrxBa1 xNb2O6

International audiencePhotorefractive self-focusing and self-trapping has proved, over the past decade, to be an efficient low power method able to provide beam control and steering. In this paper, several photorefractive samples are investigated in the aim to provide a comparative study in both continuous wave and pulsed laser light regime. Whereas their holography-like behavior can be thought of as similar, they exhibit strong differences when considering the propagation of a single high contrast narrow beam. Perovskite KNbO3 and illmenite LiNbO3 are shown to exhibit respectively self-focusing and self-defocusing features, the latter needing an erasing process to be undertaken for the experiment to be fully reproducible. Finally, SrxBa1 xNb2O6 (SBN) is shown to be the most promising sample for applications ranging from optical limiting to all optical routing, though it exhibits instabilities such as optical branching