THERMALLY-INDUCED SELF-FOCUSING AND OPTICAL BEAM INTERACTIONS IN PLANAR STRONTIUM BARIUM NIOBATE WAVE-GUIDES

We present an experimental study of thermally induced self-focusing ef fects and interactions of incoherent light beams in strontium barium n iobate waveguides. Depending on the input power, a single parallel bea m is strongly focused inside the sample up to diameters of several mic rometers. For higher input power we observe the splitting of the beam in a sequence of several spots. We demonstrate that these thermally in duced refractive-index patterns can be used to focus and deflect an in coherent guided probe beam in the waveguide with time constants below 1 ms. (C) 1998 Optical Society of America.