Kerr effect-assisted self-compression in dielectric to single-cycle pulse width and to terawatt power level in mid-IR

Abstract

The self-compression of sub-TW mid-IR (λ=4–5µm) femtosecond laser pulse in a non-linear dielectric medium was numerically modeled. Combination of the Kerr non-linearity and negative group velocity dispersion in CaF2 crystal was found to result in compression of the incident laser pulse to a 1–2-cycle pulse width. The possibility for suppression of small-scale self-focusing in conditions when the pulse power was several orders of magnitude above the critical self-focusing power was analyzed. Intrinsic concentration of free carriers was found to play important role in pulse evolution during its propagation.