title: Self-focusing collapse distance in ultrashort pulses and measurement of nonlinear index.
abstract: We analyze the method of moving focus to determine the critical power for self-focusing by means of numerical simulation and a semianalytical model. It is shown that the original interpretation of a moving focus experiment does not hold in general and that inclusion of defocusing effects due to free electrons is necessary to relate the measured data to critical power.
authors: College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA.
authors: P
authors: P
authors: Whalen
authors: J V
authors: JV
authors: Moloney
authors: M
authors: M
authors: Kolesik