RESONANT FOUR-WAVE MIXING SPECTROSCOPY: A NEW PROBE OF MOLECULAR STRUCTURE IN REGIMES OF EXTREME VIBRATIONAL EXCITATION,
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Date
1992
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
A new, folder-variant of optical-optical double resonance has been developed for the state-specific characterization of polyatomic species that contain chemically-significant quantities of vibrational $excitation^{1}$. Based upon a phase-conjugate implementation of degenerate four-wave mixing (DFWM) spectroscopy, this technique offers substantial advantages, both in terms of sensitivity and resolution, over more conventional methodologies. Despite the third-order nonlinearity inherent to the DFWM process, the tremendous resonant enhancement that accompanies this interaction enables the facile detection of doubleresonance signals even under low pressure (viz.,<10$^{-1}$Torr), bulk gas conditions. Application of this scheme will be discussed with paricular emphasis on the the rovibrational structure exhibited by $CS_{2}$ molecules that have up to 20,000$cm^{-1}$ of energy selectively deposited into their internal degrees of freedom [i.e., roughly 60\% of $D_\circ^circ$(SC--S)]. the spectral simplification afforded by the double resonance natur of this technique has also permitted a complete and systematic reanalysis of the perturbed origin band for the $CS_{2} V^{1}B_{2-}X^{1} \Sigma_g^{+}$ transition.
Description
$^{1}$ Q. Zhang. S. A. Kandel, T. W. Wasserman, and P.H.Vaccaro, J.Chem.Phys.96, 1640 (1992).
Author Institution: Department of Chemistry, Yale University
Author Institution: Department of Chemistry, Yale University