SUB-DOPPLER HETERODYNE FREQUENCY MEASUREMENTS ON THE CO2 10(0)11-00(0)01 VIBRATIONAL BAND - NEW REFERENCE LINES NEAR 3714 CM-1

A color center laser (CCL) was frequency stabilized to the Lamb-dips of transitions in the 12C16O2 10011-00001 band, with the band center near 3714 cm-1. Two CO laser, also stabilized to their CO saturation dips by the optogalvanic detection technique, were simultaneously frequency mixed with the CCL on a metal-insulator-metal (MIM) diode. Nine transition frequencies of CO2 could be determined; the absolute accuracy of the measurements is estimated to be better than 1.2 MHz. Comparison of the heterodyne frequencies with the recent Fourier transform data reveals a large discrepancy up to 30 MHz, which can be described as a systematic offset. The band center was fitted as a correction to previous calculations based on Fourier transform spectrometer (FTS) measurements. © 1991.