2001/05/31 by J. F. Corney, Ole Bang, O. Bang
Physics and Astronomy · #Advanced Fiber Laser Technologies #Nonlinear Photonic Systems #Photorefractive and Nonlinear Optics #nlin.PS #physics.optics
paper · pdf · doi:10.1364/josab.19.000812
10 Pages, 13 figures (some in two parts) new version has some typos removed and extra references and explanation added
arxiv created 2001/08/29 · openalex publication_date 2002/04/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider the propagation of broad optical beams through slab waveguides with a purely quadratic nonlinearity and containing linear and nonlinear long-period quasi-phase-matching gratings. An exact Floquet analysis of the periodic, plane-wave solution shows that the periodicity can drastically alter the growth rate of the modulational instability but that it never completely removes the instability. The results are confirmed by direct numerical simulation as well as through a simpler, approximate theory for the averaged fields that accurately predicts the low-frequency part of the gain spectrum.