Saturated-absorption spectroscopy with low-power difference-frequency radiation

摘要

We report high-resolution saturated-absorption spectra recorded by use of a few microwatts of radiation generated in a single pass by difference-frequency mixing. These results were obtained without the use of buildup cavities for the nonlinear mixing or for the saturation spectroscopy. We show high-quality saturated-absorption signals for the fundamental rovibrational band of CO_(2) near 4.3 μm. Convenient sources and frequency-conversion devices open new possibilities for sub-Doppler spectroscopy in the infrared.