Abstract

We study the discretized Vinetskii-Kukhtarev equation that can be used as a model equation for the propagation of narrow optical beams within a onedimensional homogeneous and lossless nonlinear waveguide array in photorefractive crystals with screening nonlinearity. Limiting our discussion to the first band we discovered that, due to a cascade mechanism of saturation, multiple zeros of the Peierls-Nabarro potential exist. In regions of a positive potential, stable propagation of discrete solitons which have a maximum between two sites is shown numerically. In the vicinity of zeros of this potential, both free steering of discrete solitons across the array and elastic collisions of discrete solitons are numerically observed.

© 2005 Optical Society of America