Fission of narrow high power beams into multiple solitons in a second-order nonlinear slab waveguide

Abstract

Summary form only given. One of the first nonlinear effects observed was the break-up of wide, high intensity, beams into filaments due to spatial noise present on the beam, known as modulational instability (MI), that generally occurs in any media with nonlinearities which lead to self-focusing. We have recently reported observation of MI near the phase-matching condition for second-harmonic generation in LiNbO/sub 3/ slab waveguides. For narrow beams, a different phenomenon can occur at lower intensities than MI, namely the fission of the beam into multiple solitons. For spatial solitons, the peak soliton intensity varies inversely with the soliton's spatial width, so that if the input beam contains sufficient intensity to generate multiple solitons, fission occurs. Here we report experimental observation of the break-up of high intensity beams into multiple components at thresholds consistent with soliton fission.