title: Gap solitons in quadratically nonlinear gratings: beyond the cascading limit
abstract: We consider pulse propagation in quadratically nonlinear gratings. Assuming that the phase mismatch between the fundamental and the second-harmonic frequencies deltak is large, we present a perturbation method in deltak(-1). In the well known cascading limit, terms to deltak(-1) are kept; here we keep terms to deltak(-2), which leads to another type of coupled mode equations. Numerical calculation of the full equations support our theoretical results.
authors.affiliation: Optical Sciences Centre, Research School of Physical Sciences and Engineering, The Australian National University, Canberra, ACT 0200, Australia and Department of Physics, Faculty of Science, Ehime University, Ehime 790-8577, Japan*.
authors.initials: T
authors.lastname: Iizuka
authors.lastname: de Sterke CM