This article is from the ECONOS part of the joint special issue on the European Conference on Nonlinear Optical Spectroscopy (ECONOS 2012) with Guest Editors Johannes Kiefer and Peter Radi and the II Italian Conference of the National Group of Raman Spectroscopy and Non-Linear Effects (GISR 2012) with Guest Editor Maria Grazia Giorgini.
Polarization- and time-resolved DFWM spectroscopy of the A 2Σ+− X 2Π (0,0) band transitions of nascent OH radicals generated by 266 nm laser photolysis of H2O2†
Article first published online: 15 MAY 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Special Issue: Joint special issue on the European Conference on Nonlinear Optical Spectroscopy (ECONOS 2012) and the II Italian Conference of the National Group of Raman Spectroscopy and Non-Linear Effects (GISR 2012)
Volume 44, Issue 10, pages 1349–1355, October 2013
How to Cite
Maksyutenko, P., Radi, P. P., Kozlov, D. N. and Kouzov, A. P. (2013), Polarization- and time-resolved DFWM spectroscopy of the A 2Σ+− X 2Π (0,0) band transitions of nascent OH radicals generated by 266 nm laser photolysis of H2O2. J. Raman Spectrosc., 44: 1349–1355. doi: 10.1002/jrs.4299
- Issue published online: 22 OCT 2013
- Article first published online: 15 MAY 2013
- Manuscript Accepted: 7 MAR 2013
- Manuscript Received: 5 MAR 2013
- Science and Technology Cooperation Program Switzerland-Russia. Grant Number: GA 128546
- Russian Foundation for Basic Research. Grant Numbers: #11-02-01296, # 11-03-00448
- four-wave mixing;
The potential of a non-linear spectroscopic technique – degenerate four-wave mixing (DFWM) spectroscopy – for photo-dissociation studies is investigated. By applying a carefully considered control of the input beam polarizations, the technique is used to measure the line shapes of specific rovibrational transitions in the A 2Σ+ − X 2Π (0,0) band of nascent OH radicals upon pulsed photo-dissociation of H2O2. The photofragmentation is performed by linearly polarized radiation at 266 nm, and DFWM spectra are observed at various time delays. In contrast to linear spectroscopic methods, isotropic and anisotropic components of the non-linear susceptibility tensor are separately accessible by using appropriate polarization geometries. In particular, four-wave mixing signals can be generated that are exclusively due to the occurrence of the transient anisotropy of the recoil velocity and angular momentum vector distributions of the fragments emerging from the dissociation reaction. The observed line shapes in isotropic and anisotropic DFWM spectra are governed by the Doppler effect and vectorial correlations between the parent H2O2 molecule's transition dipole moment, the OH fragments’ recoil velocity and angular momentum, as well as by the processes of collision-induced rotational and translational relaxation. Copyright © 2013 John Wiley & Sons, Ltd.