title: Higher-order Kerr effect and harmonic cascading in gases.
abstract: The higher-order Kerr effect (HOKE) has recently been advocated to explain measurements of the saturation of the nonlinear refractive index in gases. Here we show that cascaded third-harmonic generation results in an effective fifth-order nonlinearity that is negative and significant. Higher-order harmonic cascading will also occur from the HOKE, and the cascading contributions may significantly modify the observed nonlinear index change. At lower wavelengths, cascading increases the HOKE saturation intensity, while for longer wavelengths cascading will decrease the HOKE saturation intensity.
authors.affiliation: DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Lyngby DK-2800 Kgs, Denmark. moba@fotonik.dtu.dk
authors.forename: Morten
authors.initials: M
authors.lastname: Bache
authors.forename: Falk
authors.initials: F
authors.lastname: Eilenberger
authors.forename: Stefano
authors.initials: S
authors.lastname: Minardi