Amplified infrared generation in a laser–plasma interaction simulated based on photo-current model

Abstract

The present study discussed a theoretical model to simulate the interaction of an ultra-short femtosecond laser pulse with a slab of neutral Ar gas. The calculation was based on using the Particle in Cell-Monte Carlo Collision (PIC-MCC) method to investigate the possibility of infrared emission. It was found that besides several emissions that are inevitably obtained from a high-density Ar-based plasma medium, resonance radiation can be achieved at about 165 THz whenever the stimulated Raman scattering (SRS) based half-harmonic and rippled density wavenumber are involved in phase match condition with the fundamental laser frequency. Among several parameters examined to amplify the resonance emission, the symmetry breaking of electric field (SBEF) and turning up the input intensity to about 1018 W/cm2 proved more efficient infrared emission. It turned out that compared to the SBEF effect, an almost three times stronger infrared intensity can be obtained using more intensive laser pulses. The transverse profile for half-harmonic emission and resonant radiation is presented. It is observed that, the infrared radiation has an off-axis profile. At an intensity of 1018 W/cm2, the effects of hot electrons and the nonlinear Kerr refractive index have been presented. It was found that these two parameters limit the generation mechanism at the beginning of the plasma and at the end of the interaction medium, respectively. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.