Parametric conversion of the frequency of tunable infrared radiation to the ultraviolet range in potassium vapor

Radiation emitted by tunable cw CO₂ and CO lasers was frequency-converted to the ultraviolet range (300 nm) in potassium vapor by parametric mixing using pump radiation exciting twophoton resonances 8S_1/2,9S_1/2, and 7D_3/2,5/2 in the potassium atom. Use was made of the proximity of the frequency of the converted radiation to the frequency of one-photon transitions to the levels 10P_1/2,3/2 and 11P_1/2,3/2.