Far infrared difference frequency generation

One method of laser isotope separation requires a far FIR, nearly monochromatic source of radiation having an energy per pulse on the order of tens of microjoules. An attractive method of producing this required energy is difference frequency generation using a CO and a CO2 laser as sources.1,2 The difference frequency generation could occur in a nonlinear material such as CdGeAs2 or AgGaSe2. The engineering development of the lasers and the results obtained from second harmonic generation as well as difference frequency generation experiments are described. The major emphasis in the development of the CO laser was the increase in the peak power. However, the major emphasis in the development of the CO2 laser was the attainment of consistently good spatial and temporal mode quality.