Abstract

Saturation spectroscopy employing a CO₂ laser and modulation sidebands at microwave frequencies achieves sub-Doppler resolution^[1] in the vicinity of 30 THz (between 9 µm and 11 µm). This also is the frequency range of characteristic fundamental vibrations of several molecules belonging to groups of higher symmetry; therefore it is possible to apply this technique to the investigation of splitting effects not observable so far by infrared spectroscopy. In addition, it provides an absolute frequency measurement accurate to less than 200 kHz.

© 1992 IQEC