Abstract

Now it is widely accepted that nonlinear optical waveguide arrays (NOWAs) exhibit interesting phenomena which can be exploited in all-optical signal processing. Many investigations were devoted to NOWAs with cubic nonlinearities. The existence of self-localized states where only the amplitude in a few waveguides differs considerably from that of the background have been demonstrated and their properties were systematically analyzed (see e.g. [1,2] and refs, therein). Another aspect in contemporary nonlinear optics is connected with quadratic or χ⁽²⁾ - nonlinearities which are believed to possess a genuine potential in all-optical device concepts [3,4]. However, the most studies in that field dealt with continuum rather than discrete media.

© 1998 Optical Society of America