We demonstrate non-degenerate photon-pair generation by spontaneous parametric down conversion in a silver gallium sulfide AgGaS2 crystal. By tuning the pump wavelength, we achieve phase matching over a large spectral range. This allows to generate idler photons in the mid-infrared spectral range above 6 μm wavelength with corresponding signal photons in the visible. Also, we show photon pair generation with broad spectral bandwidth. These results are a valuable step towards the development of quantum imaging and sensing techniques in the mid-infrared.
@article{arxiv.2110.01511,
title = {Mid-Infrared Photon-Pair Generation in AgGaS$_2$},
author = {Mohit Kumar and Pawan Kumar and Andres Vega and Maximilian A. Weissflog and Thomas Pertsch and Frank Setzpfandt},
journal= {arXiv preprint arXiv:2110.01511},
year = {2022}
}