Upconversion of broadband infrared spectra.

An experimental device successfully upconverts ir radiation in the 3.2-5.0-microm wavelength range simultaneously to "visible" light at 0.80-0.88 microm, while preserving frequency coding and is thus applicable to ir spectroscopy. The 1.8-microm bandwidth of ir radiation that is upconverted without temperature or phase match tuning is the largest yet reported. The over-all system quantum efficiency of the upconverter/spectrometer system is 0.01% and could be improved to 0.4%.