Molecular near-infrared transitions determined with sub-kHz accuracy

Abstract

Precise molecular transition frequencies are of great interest in the test of fundamental physics and also in various applications. Two well isolated ro-vibrational transitions of ${}^{12}$C${}^{16}$O at 1.57 $\mu$m, R(9) and R(10) in the second overtone band molecule, were measured by a comb-locked cavity ring-down spectrometer. Despite the weakness of the lines (Einstein coefficient $A\simeq 0.008$ s${}^{-1}$), Lamb-dip spectra were recorded with a signal-to-noise ratio over 1000, and the line positions were determined to be 191 360 212 763.7 and 191 440 612 664.8 kHz respectively, with an uncertainty of 0.5 kHz ($\delta \nu /\nu =2.6\times 10^{-12}$). The present work demonstrated the possibility to explore extensive molecular lines in the near-infrared with sub-kHz accuracy.

References in corpus (3)

• Stability of the proton-to-electron mass ratio
• High-precision C17O, C18O and C16O measurements in young stellar objects: analogues for CO self-shielding in the early solar system
• Complete ${\alpha }^{6}m$ corrections to the ground state of H${}_2$

Cited by in corpus (1)

• Optically Derived Radio-Frequency Benchmark in Methanol: A Sub-kHz Reference for Astrophysical Tests of Fundamental Physics