Multikilowatt mid infrared emission with high pump photon conversion efficiency (∼ 15 percent) has been obtained by difference frequency generation in CdGeAs
2utilizing the double wavelength output from a grating tuned twin-cavity TEA CO
2system, one signal of which is frequency doubled to provide efficient synchronized sources for both pump and idler. Tuning over a spectral range

m can be achieved and further extended to 17 μm using 12.8 μm emission from an efficient TEA CO
2pumped NH
3laser.