Simulations of 10 μm filaments in a realistically modeled atmosphere

Abstract

We numerically study the formation and propagation dynamics of 10 μm filaments in the atmosphere. We investigate filament formation of multi-Joule 100 fs and 1 ps duration pulses over propagation lengths of 100 m and find that the carrier self-steepening regularization mechanism predicted for 4 μm wavelengths still holds. In our study we include multiple physical effects ignored in the past, such as rotational Raman and avalanche ionization. In addition we incorporate in our simulations the most detailed dispersive model available for atmospheric air, which includes multiple species, such as O2, N2, Ar, CO2, CO, and CH4, for a variety of humidity levels. Results presented here are expected to have a significant impact in the wider field of nonlinear optics where the use of mid-infrared lasers is rapidly growing.