70 MW-level picosecond mid-infrared radiation generation by difference frequency generation in AgGaS2, BaGa4Se7, LiGaSe2, and LiGaS2

Michal JelÃ­nek; Milan Frank; VÃ¡clav KubeÄek; OndÅej NovÃ¡k; Jaroslav Huynh; Martin Cimrman; Michal Chyla; Martin SmrÅ¾; TomÃ¡Å¡ Mocek

doi:10.1109/JPHOT.2025.3542540

paper

70 MW-level picosecond mid-infrared radiation generation by difference frequency generation in AgGaS2, BaGa4Se7, LiGaSe2, and LiGaS2

arXiv:2503.08584 · doi:10.1109/JPHOT.2025.3542540

Abstract

Comparative study of nonlinear crystals for picosecond difference frequency generation in mid-IR is presented. Nonlinear crystals of AgGaS $_{2}$ , BaGa $_{4}$ Se $_{7}$ , LiGaSe $_{2}$ , and LiGaS $_{2}$ were studied. Samples of AgGaS $_{2}$ , BaGa $_{4}$ Se $_{7}$ , LiGaSe $_{2}$ , and LiGaS $_{2}$ were tested in thee sets having lengths of 2, 4, or 8 mm. In order to investigate the dependence of efficiency on the crystal length, three sets of crystals with lengths of 2, 4, or 8 mm were tested. The developed tunable DFG system was driven by the 1.03 $I^¼$ m, 1.8 ps, Yb:YAG thin-disk laser system operated at the repetition rate of 10 or 100 Hz. As the best result, picosecond mid-IR pulses at a wavelength of $\sim$ 7 $I^¼$ m with the energy up to 130 $I^¼$ J corresponding to the peak power of $\sim$ 72 MW were generated using the 8 mm long LiGaS $_{2}$ crystal. Using the BaGa $_{4}$ Se $_{7}$ crystal, DFG tunability in the wavelength range from 6 up to 13 $I^¼$ m was achieved.

7 pages, 5 figures