Resonantly enhanced terahertz four-wave mixing in fluorides

Eva Noskovicova; Martin Koys; Monika Jerigova; Dusan Velic; Dusan Lorenc

paper

Resonantly enhanced terahertz four-wave mixing in fluorides

arXiv:2405.10733

Abstract

Converting a THz signal into the optical domain is of great interest for THz sensing and spectroscopy. Here intense broadband THz pulses with a central frequency of $Ω$ $_{T H z}$ are mixed with an optical pump at $ω$ $_{p}$ and a signal is observed at a wavelength of $ω$ $_{s}$ = 2( $ω$ $_{p}$ - $Δ ω$ $_{p}$ ) - $Ω_{T H z}$ with the detuning $ω$ $_{p}$ - $Δ ω$ $_{p}$ being due to pump pulse spectral broadening. The observed THz-FWM signal close to 400 nm is shown to result from a resonantly amplified four-wave mixing in CaF $_{2}$ , BaF $_{2}$ and MgF $_{2}$ .