Non-degenerate SPDC photon-pair source for UV-A illumination

We present a frequency-correlated non-degenerate photon-pair source consisting of a second-order nonlinear crystal that generates ultraviolet UV-A and infrared light via spontaneous parametric down-conversion (SPDC). Quantum imaging and sensing techniques like quantum imaging with undetected light and quantum ghost imaging leverage wavelength correlations between down-converted photon pairs to decouple sensing and detection wavelengths, thereby exploiting established camera technology within the visible spectrum. Our results open up quantum sensing application scenarios in the ultraviolet domain, with potential implications for advancements in biomedical and non-destructive testing fields.