Multi-terawatt femtosecond 10 µm laser pulses by self-compression in a CO2 cell

Abstract

We propose and numerically investigate a novel direct route to produce multi-terawatt femtosecond self-compressed 10 mu m laser pulses suitable for the next generation relativistic laser-plasma studies including laser-wakefield acceleration at long wavelengths. The basic concept involves selecting an appropriate isotope of CO2 gas as a compression medium. This offers a dispersion/absorption landscape that is shifted in frequency relative to the driving CO2 laser used for 10 mu m picosecond pulse generation. We show numerically that as a consequence of low losses and a broad anomalous dispersion window, a 3.5 ps duration pulse can be compressed to similar to 300 fs while carrying similar to 7 TW of peak power in less than 7 m. An interplay of self-phase modulation and anomalous dispersion leads to a similar to 3.5 times compression factor, followed by the onset of filamentation near the cell exit to get below 300 fs duration. (c) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement