Comb-locked Cavity-assisted Double Resonance (coca-dr) Spectroscopy Of Molecules With Khz Accuracy

Hu, Shui-Ming

Permalink

https://hdl.handle.net/2142/111067 Copy

Description

Title

Comb-locked Cavity-assisted Double Resonance (coca-dr) Spectroscopy Of Molecules With Khz Accuracy

Author(s)

Hu, Shui-Ming

Contributor(s)

• Tan, Yan
• Wang, Jin
• Sun, Yu Robert
• Liu, An-Wen
• Hua, Tian-Peng
• Cheng, Cunfeng
• Perevalov, Valery
• Hu, Changle

Issue Date

2021-06-23

Keyword(s)

Mini-symposium: Precision Spectroscopy for Fundamental Physics

Abstract

\begin{wrapfigure}{r}{0pt} \includegraphics[scale=0.6]{coca.eps} \end{wrapfigure} Double resonance (DR) spectroscopy has been frequently applied in state-selective excitation and to reach energy levels forbidden to single-photon transitions. Due to the low cross section of two-photon transitions, usually high-power pulsed lasers are needed, which prevent high-precision measurements. Here we present a newly developed comb-locked cavity-assisted double resonance (COCA-DR) spectroscopy technique, which simultaneously lock two near-ir diode lasers to a high-finesse cavity and an optical frequency comb. Doppler-free spectra of molecules with selected speeds along the laser beam were observed, and the DR line positions were determined with a frequency accuracy of 3 kHz. The V and $\Lambda$ type DR measurements of CO overtone transitions near 1.6~$\mu$m were used to verify the frequency accuracy of lines measured by COCA-DR. Transitions to the highly-excited (60025) ($v_{CO}=8$) ``dark'' state of the CO$_2$ molecule were measured using the (30013) vibrational state as the intermediate. Rotational energies of the (60025) state were determined for the first time, and they were compared with the calculated values based on effective operators. The study paves the way to pump-probe measurements of molecules with unprecedented precision.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111067

DOI

10.15278/isms.2021.WI14

Owning Collections