High-contrast few-cycle pulse compression in CaF 2 : a numerical study
Munkhbayar Gombosuren, Tsendsuren Khurelbaatar, Unurbileg Darmaa, Mikhael Korolkov, Dmitri Mogilevtsev, Jav Davaasambuu, Tuvjargal NorovsambuuIntense, high-contrast few-cycle pulses are essential for ultrafast science. Multi-plate post-compression has been developed mainly to reach the shortest pulse duration, while the temporal contrast of the output, critical for sensitive strong-field experiments, remains underexplored. Using the three-dimensional unidirectional pulse propagation equation, we compare spectral broadening in multi-plate CaF 2 and SiO 2 at 800 nm under identical conditions. CaF 2 yields near-transform-limited 4.7 fs pulses with a temporal contrast three to five orders of magnitude higher than SiO 2 over a 70–150 fs delay. This arises from the negligible Raman response of crystalline CaF 2 , whose purely electronic broadening avoids the incoherent pedestal that dispersion compensation cannot remove, identifying crystalline fluorides as promising media for high-contrast few-cycle pulse compression.