Single-beam coherent anti-Stokes Raman scattering (CARS) spectroscopy of gas-phase CO2 via phase and polarization shaping of a broadband continuum
✍ Scribed by Sukesh Roy; Paul J. Wrzesinski; Dmitry Pestov; Marcos Dantus; James R. Gord
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 258 KB
- Volume
- 41
- Category
- Article
- ISSN
- 0377-0486
- DOI
- 10.1002/jrs.2587
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✦ Synopsis
Abstract
Coherent anti‐Stokes Raman scattering (CARS) spectroscopy of gas‐phase CO~2~ is demonstrated using a single femtosecond (fs) laser beam. A shaped ultrashort laser pulse with a transform‐limited temporal width of ∼7 fs and spectral bandwidth of ∼225 nm (∼3500 cm^−1^) is employed for simultaneous excitation of the CO~2~ Fermi dyads at ∼1285 and ∼1388 cm^−1^. CARS signal intensities for the two Raman transitions and their ratio as a function of pressure are presented. The signal‐to‐noise ratio of the single beam–generated CO~2~ CARS signal is sufficient to perform concentration measurements at a rate of 1 kHz. The implications of these experiments for measuring CO~2~ concentrations and rapid pressure fluctuations in hypersonic and detonation‐based chemically reacting flows are also discussed. Copyright © 2010 John Wiley & Sons, Ltd.