DUAL-COMB UP-CONVERSION DETECTION OF FUNDAMENTAL MOLECULAR TRANSITIONS

Chen, Zaijun

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https://hdl.handle.net/2142/104552 Copy

Description

Title

DUAL-COMB UP-CONVERSION DETECTION OF FUNDAMENTAL MOLECULAR TRANSITIONS

Author(s)

Chen, Zaijun

Contributor(s)

Picqué, Nathalie ; Hänsch, Theodor W.

Issue Date

2019-06-17

Keyword(s)

Instrument/Technique Demonstration

Abstract

"\begin{wrapfigure}{r}{0pt} \includegraphics[scale=0.6]{spec6.eps} \end{wrapfigure} We present a new approach to mid-infrared dual-comb spectroscopy. Strong fundamental ro-vibrational transitions are interrogated in the mid-infrared 3-$\mu$m region, while the detection is performed in the near-infrared telecommunication region where sensitive opto-electronic tools are available. Using difference-frequency generation, a near-infrared comb is converted to the range of 2700-3400 \wn, where it interacts with the sample before being converted back to the telecommunication region. There, it beats with a second comb of slightly different line spacing for multiheterodyne detection. The broadband spectra obtained within arbitrarily long averaging time show resolved comb lines, a frequency scale calibrated within the accuracy of an atomic clock and a negligible contribution of the instrument line shape, as in previous reports using our recent scheme of feed-forward stabilization\footnote{Z. Chen, M. Yan, T. W. H\""{a}nsch, and N. Picqu\'{e}, A phase-stable dual-comb interferometer, Nat Commun 9, 3035 (2018).}$^{,}$\footnote{Z. Chen, T. W. H\""{a}nsch, and N. Picqu\'{e}, Mid-infrared feed-forward dual-comb spectroscopy, Proc Natl Acad Sci USA 116, 3454-3459 (2019).}. A spectrum (Fig. a, expanded view on a single comb line on the radio-frequency scale in Fig.b) in the region of the {\it Q }-branch of the \nub{3} band of $^{12}$CH$_{4}$, is measured within 1000 s. The molecular profiles are sampled by the comb at a resolution of 3.3 10$^{-3}$ \wn (Fig.c) across a total span of 50 \wn, with an average signal-to-noise ratio of 2540. Comparisons with direct mid-infrared detection will be discussed."

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/104552

DOI

10.15278/isms.2019.MJ02

Copyright and License Information

Copyright 2019 Zaijun Chen

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