Wavelength selectable Raman laser in the ultraviolet (266 to 321nm)

In this paper, a solid-state UV Raman laser pumped at by a Q-switched 532 nm laser that utilizes intracavity sum-frequency mixing to generate more than 20 wavelengths in range 266-321nm, is reported. The Raman laser consisted of a KGd(WO₄)₂ Raman crystal and beta-barium borate (BBO) crystal positioned in a resonator. The input coupler is highly transmissive at 532 nm and highly reflective for the first three Stokes orders. The second harmonic or sum frequencies of the intracavity Stokes and fundamental fields were coupled from the resonator using a UV reflecting dichroic mirror placed between the BBO crystal and the Raman crystal. We conclude that the intracavity Raman laser provides a wavelength versatile source of UV at wavelengths spanning and neighbouring the UV-B (285-315nm).