Saturated Cavity Ring-Down Spectroscopy of 12C16O2 Near 1.57 Μm

We present the saturated absorption spectroscopy of the 30012 <- 00001 band of (12)C(16)O(2 )by a comb-locked cavity ring-down spectrometer near 1.57 mu m. Positions of 37 lines with rotational quantum numbers up to 68 were determined with an accuracy of a few kHz. Comparisons of the ro-vibrational energy levels determined in this work with the Doppler-limited experimental values from literature and those from the CDSD2019 databank are given. Deviations exceeding 1 MHz were observed in the transitions blended by other carbon dioxide isotopologues.