Femtosecond filamentation in air and higher-order nonlinearities.
According to a recent experiment, the instantaneous electronic Kerr effect in air exhibits a strong intensity dependence, the nonlinear refractive index switching sign and crossing over from a self-focusing to a defocusing nonlinearity. A subsequent theoretical work has demonstrated that this has paradigm-changing consequences for the understanding of filamentation in air, so it is important to subject the idea of higher-order nonlinearities to stringent tests. Here we use numerical modeling to propose an experiment capable of discriminating between the standard and the new intensity-dependent Kerr-effect models.
Kolesik
M
M
College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA. kolesik@acms.arizona.edu
Wright
E M
EM
Moloney
J V
JV