2014/12/17 by Michael Hofmann, Hofmann, Michael, Carsten Brée +1
Physics and Astronomy · #Atomic Physics (physics.atom-ph) #FOS: Physical sciences #Optics (physics.optics) #physics.atom-ph #physics.optics
paper · pdf · doi:10.48550/arxiv.1412.5345
arxiv created 2014/12/17 · arxiv updated 2014/12/18
We demonstrate that Freeman resonances have a strong impact on the nonlinear optical response in femtosecond filaments. These resonances decrease the transient refractive index within a narrow intensity window and strongly affect the filamentation dynamics. In particular, we demonstrate that the peak intensity of the filament can be clamped at these resonances, hinting at the existence of new regimes of filamentation with electron densities considerably lower than predicted by the standard model. This sheds a new light on the phenomenon of filamentary intensity clamping and the plasmaless filaments predicted by the controversial higher-order Kerr model.