https://doi.org/10.1140/epjd/s10053-022-00552-x
Regular Article – Atomic Physics
Saturation spectroscopy of R(0), R(2) and P(2) lines in the (2-0) band of HD
Department of Physics and Astronomy, LaserLab, Vrije Universiteit, De Boelelaan 1081, 1081, Amsterdam, HV, The Netherlands
Received:
10
October
2022
Accepted:
7
November
2022
Published online:
18
November
2022
Lamb-dips of R(0), R(2) and P(2) rovibrational transitions in the (2-0) overtone band of the HD molecule are measured at cryogenic temperatures using the technique of NICE-OHMS spectroscopy. Resulting transition frequencies are 
kHz for R(0), 
kHz for R(2) and 
kHz for P(2). Small, but systematic deviations (at 1.7
level) are found from advanced ab initio calculations, supporting results from previous studies probing other lines in the (2-0) band. From a combination difference between the R(0) and P(2) lines, an accurate value for rotational-level spacing in the 
ground state is determined, of 
kHz, well in agreement with theory (at 0.6). Based on the observation of the dispersive line shape of R(0), the status of proposed models for the elusive line shapes of saturated transitions in HD is discussed.
© The Author(s) 2022
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