Attenuated total reflectance spectroscopy of liquids using a mid-IR dual frequency comb spectrometer

Herman, Daniel I.

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https://hdl.handle.net/2142/100472 Copy

Description

Title

Attenuated total reflectance spectroscopy of liquids using a mid-IR dual frequency comb spectrometer

Author(s)

Herman, Daniel I.

Contributor(s)

• Coddington, Ian
• Newbury, Nathan R.
• Baumann, Esther
• Giorgetta, Fabrizio
• Waxman, Eleanor
• Ycas, Gabriel

Issue Date

2018-06-19

Keyword(s)

Mini-symposium: Frequency-Comb Spectroscopy

Abstract

Since its inception, dual comb spectroscopy (DCS) has enabled a variety of new spectroscopic applicationsa . Here, we report on the extension of a broad bandwidth, high coherence DCS system to mid-infrared (MIR) spectroscopy of liquidphase samples in the C-H stretch region (∼2800 to 3100 cm−1 ). Each comb originates from a self-referenced Er:fiber oscillator with a repetition rate of 200 MHz. Using a two-branch difference frequency generation (DFG) configuration, each comb is downconverted to the MIR, which yields output tunable from 2.6 to 5.2 µm with up to 100 mW in a single instantaneous bandwidth. Using attenuated total reflectance (ATR) coupling techniques, spectra of the pure isopropanol C-H stretch are recorded in 1.5 second integration periods consisting of ∼100 phase-corrected, averaged interferograms and show excellent agreement with reference spectra. A fitted average of 50 integration periods is shown in the abstract image. Initial estimates show that baseline fluctuations on the order of 2% will dominate sensitivity models. Further, we demonstrate progress towards the use of our DCS system as an analytical tool for organic reaction monitoring. We use an aldol condensation reaction as a test case where we detect Csp3 -H stretches in the reactant (acetone) and Csp2 -H stretches in the product (mesityl oxide). Methods for quantitative analysis of the aldol condensation will be discussed. Finally, this talk will explore the compatibility of DCS and newly-developing micro-reactor waveguide technology.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100472

DOI

10.15278/isms.2018.TA09

Copyright and License Information

Copyright 2018 Daniel I. Herman

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