High-precision mid-ir molecular spectroscopy with traceability to primary frequency standards using sub-hz frequency comb-stabilized qcls

Darquie, Benoit

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https://hdl.handle.net/2142/100535 Copy

Description

Title

High-precision mid-ir molecular spectroscopy with traceability to primary frequency standards using sub-hz frequency comb-stabilized qcls

Author(s)

Darquie, Benoit

Contributor(s)

• Amy-Klein, Anne
• Pottie, Paul-Eric
• Xu, Dan
• Lee, Won-Kyu
• Le Targat, Rodolphe
• Le Coq, Yann
• Abgrall, Michel
• Tokunaga, Sean
• Lopez, Olivier
• Santagata, Rosa
• Tran, Dang Bao An

Issue Date

2018-06-19

Keyword(s)

Mini-symposium: Frequency-Comb Spectroscopy

Abstract

High-precision measurements with molecules may refine our knowledge of various fields of physics, from atmospheric and interstellar physics to the standard model or physics beyond it. Many of them can be cast as absorption frequency measurements, particularly in the mid-infrared molecular fingerprint region, creating the need for narrow-linewidth lasers of well-controlled frequency. We present a new technology for precision vibrational spectroscopy using quantum cascade lasers (QCLs)a . Via an optical frequency comb, a QCL is stabilized at the sub-Hz level on an ultra-stable near infrared reference signal provided by the French metrology institute (SYRTE) to our laboratory and transferred through a 43-km long fiber cableb . The stability of the reference is transfered to the QCL, which therefore exhibits a relative frequency stability lower than 2 × 10−15 between 1 and 100 s. Moreover its absolute frequency is known with an uncertainty below 10−14 thanks to the traceability to the primary standards of SYRTE. The setup allows the QCL to be widely scanned over ∼ 1 GHz while maintaining the highest stabilities and accuracies. We report saturated absorption spectroscopy investigations conducted around 10 µm on osmium tetroxyde in a Fabry-Perot cavity and methanol in a multipass cell at low pressures ranging from 0.01 to 10 Pa, allowing central frequencies, pressure shifts and broadenings to be determined with record uncertainties. By combining wide tuneability, high sensitivity and resolution, this setup constitutes a key technology for precise spectroscopic measurements with molecules.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100535

DOI

10.15278/isms.2018.TG02

Copyright and License Information

Copyright 2018 Benoit Darquie

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