Absolute frequency metrology of buffer-gas-cooled molecular spectra at 1 kHz accuracy level

Abstract

High-resolution molecular spectroscopy with cryogenic setups is hampered by the lack of a skilled interrogation tool. Here, the authors demonstrate absolute metrology of cold rovibrational spectra at 1 kHz accuracy level, by coupling a Lamb-dip saturated-absorption cavity ring-down spectrometer to a buffer-gas cooling source.