Abstract

Optical beams diffract on propagation in homogeneous slab waveguides unless there are optical nonlinearities present which lead to beam selftrapping (spatial solitons) and the beam intensity is high enough for nonlinear effects to counteract the diffraction. It was shown by Christodoulides and Joseph in 1988 that light propagating in arrays of coupled channel waveguides could undergo diffractionless propagation and self-focusing due solely to the dispersion relations of the array.¹ This has recently spurred interest in spatial solitons in such systems, and controlled propagation has been demonstrated in AlGaAs and polymer waveguide arrays.^2,3 In this paper we demonstrate these unique linear propagation properties in arrays of coupled channel waveguides in Ti:in- diffused LiNbO₃. This material with controlled diffraction should have multiple applications in addition to the generation of solitons, for example to electro-optic and acousto-optic beam deflectors etc.

© 2002 Optical Society of America