Tunable coherent ir source based upon four-wave parametric conversion in alkali metal vapors

A new type of near-ir source producing a coherent output with a spectrally narrow (∼ 0.1 cm-1) and continuously tunable frequency is described. It utilizes a four-wave mixing process in alkali metal vapor with input beams provided by two nitrogen-laser-pumped dye lasers. Tunable output has so far been observed in the range 2-5.4 μ. © 1973 American Institute of Physics.