Optical sum frequency mixing as a source of tunable coherent vacuum ultraviolet radiation
Stickel, Robert Eugene
Dunning, F. Barry
Master of Arts
The production of intense, coherent, tunable, monochromatic radiation at wavelengths from 21 to 217 nm by three wave optical sum mixing in a crystalline solid is described. Two separate laser inputs are mixed in a crystal of potassium pentaborate tetrahydrate (KB5) to produce radiation at a frequency equal to the sum of the two input frequencies. The mixing of two dye lasers, one dye laser with a nitrogen laser and one frequency doubled dye laser with a ruby laser are investigated. Combinations of input wavelengths, propagation direction in the crystal and crystal temperature which yield efficient phasematched mixing are presented. Monochromatic outputs of 1^1 to 1^13 photons per second have been produced. Theoretical calculations are discussed which suggest that wavelengths as short as 18 nm may be conveniently generated using this technique.