Two-dimensional spatial solitons with second-order nonlinearities

Abstract

In addition to harmonic generation and frequency mixing, intense light beams propagating in χ⁽²⁾ nonlinear media exhibit a variety of self- and cross-phase-modulation effects that until recently were commonly thought to occur only in χ⁽³⁾ interactions. One important example is the propagation of solitonlike waves in which the fundamental and second-harmonic waves mutually focus and trap each other. The (1 + 1) trapping (i.e., one transverse dimension and one propagation dimension) yields both spatial and temporal solitons that can, in principle, occur in planar waveguides and fibers, respectively.