Cavity-enhanced double resonance spectroscopy of HD

Abstract

Precision spectroscopy of molecular hydrogen can be used to test the quantum electrodynamics theory and determine the proton-to-electron mass ratio in a four-body system. Cavity-enhanced double-resonance spectroscopy is proposed to determine highly-excited rotation-vibration energies of HD with high precision. As a demonstration, the V-type comb-locked cavity-assisted double resonance (COCA-DR) spectroscopy of HD is measured by pumping the P(1) (2-0) line and probing the R(1) line in the same overtone band. The sum value of the two transition frequencies is determined to be 426 889 423 917 (26) kHz, representing a new test of theoretical calculations.

GRAPHICAL ABSTRACT

Keywords:

• Molecular hydrogen
• precision measurements
• cavity-enhanced double resonance
• fundamental physics

Acknowledgments

The authors acknowledge Prof. K. K. Lehmann for discussion of the density matrix calculations.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was jointly supported by the National Natural Science Foundation of China (11974328 and 21688102), by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDC07010000, XDB21020100).