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Updated: Jun 20, 2026

Infrared Degenerate Four-wave Mixing with Upconversion Detection for Quantitative Gas Sensing
Published on: March 22, 2019
High-resolution degenerate four-wave mixing spectral profiles of OH
Abstract:
High-resolution degenerate four-wave mixing spectra of the R(1)(9) A(2)Sigma(+) ? X(2)II(0,0) transition of OH have been measured in a hydrogen/oxygen flame at atmospheric pressure where the Doppler and homogeneous linewidths are of comparable magnitude. The observed sub-Lorentzian Doppler-free line profile is fit well by existing perturbative models by using homogeneous broadening consistent with two-photon absorption measurements. Power broadening of the spectral profile with increasing pump-beam intensity was observed and is compared with predictions from a nonperturbative two-level model.
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