Frequency conversion of cw CO2 laser radiation from λ=10.6 μ to the 276.8 nm range in a mixture of thallium and cesium vapor

Frequency conversion of cw CO₂ laser radiation to the 276.8 nm ultraviolet range was achieved in a mixture of thallium and cesium vapor by parametric mixing with radiation from a rhodamine 6G dye laser. Two-photon resonance of the pump radiation with the 6P_1/2–7P_3/2 forbidden transition and the proximity of the converted radiation frequency to the frequency of the 6D_3/2–7P_3/2 transition in the thallium atom were utilized. Cesium vapor was used to match the refractive indices of the interacting waves.