Saturation-dip measurements in the 2ν<Subscript>2</Subscript> overtone band of OCS with a CO<Subscript>2</Subscript>-laser/microwave-sideband spectrometer

We have employed a CO₂-laser/microwave-sideband spectrometer to carry out saturation-dip sub-Doppler measurements of a number of 2₂ overtone transitions of OCS in the 10-m region. The OCS frequencies have been obtained with an absolute accuracy of order ±37 kHz, as determined from a careful analysis of the combined uncertainties in the frequency of our Lamb-dip-locked laser and the centers of the observed OCS saturation signals. Our ±37 kHz measurement accuracy is consistent with literature OCS sub-Doppler data obtained on a similar instrument. The results serve to extend the comb of precise reference frequencies in the 10-m region and to determine the magnitudes of systematic and random uncertainties of our CO₂ laser. PACS 07.57.Ty; 33.20.Ea; 42.62.Fi