Periodic spatial instabilities of high intensity beams in nonlinear waveguides

Abstract

Summary form only given. In self-focusing media a plane wave of infinite extent breaks-up into a periodic array of individual intensity maxima. This has been reported in bulk quadratic and photorefractive media, but not in slab waveguides for which analytical theories exist. Modulational instability (MI) leading to periodic structures has been demonstrated for SHG in LiNbO/sub 3/ slab waveguides, in excellent agreement with theory. Furthermore, by seeding the periodic patterns, the MI gain coefficients were measured, and again good agreement with theory.