Search results for "Slowly varying envelope approximation"
showing 3 items of 3 documents
Models for supercontinuum generation beyond the slowly-varying-envelope approximation
2014
International audience; We show numerically that both the modified Korteweg–de Vries and the sine-Gordon models are conducive to the generation of supercontinua with spectral bandwidths of several octaves, when an intense short pulse is launched as the initial condition. These models beyond the slowly-varying-envelope approximation could play an important role in modeling supercontinuum generation in gas-filled hollow waveguides.
Analytical investigation of solitary waves in nonlinear Kerr medium
2004
Abstract We study analytically the solution of nonlinear equation which result from the propagation of electromagnetic waves within a nonlinear Kerr medium. The medium is characterized by a dielectric constant which varies periodically and depends on the local field intensity. As a first step, we detail the resolution of the nonlinear equations with a quadratic nonlinearity. After that, we apply the slowly varying envelope approximation to obtain a Sine–Gordon equation. In this kind of nonlinearity, a gap solitons occurs. Moreover we verify that the solutions of the nonlinear equation for all frequencies within the gap are solitons solutions. After that we study the conditions of apparition…
Practical formula for the evaluation of high-order multiphoton absorption in thin nonlinear media
2009
We present an analytical formula for the fast and accurate evaluation of nonlinear absorption in materials exhibiting an admixture of different multiphoton processes. This approach is specifically addressed for its use in thin films when the slowly varying envelope approximation applies. The contribution of absorptions of distinct order is conveniently averaged in order to use well-known expressions for a single multiphoton process. In the latter case, therefore, our simple expression is reduced toward the exact solution.