Mode-focusing in molecules by feedback-controlled shaping of femtosecond laser pulses

Phys Chem Chem Phys. 2005 Oct 21;7(20):3574-9. doi: 10.1039/b509388k. Epub 2005 Sep 8.

Abstract

The feasibility of mode-selective excitation with broadband femtosecond laser pulses is demonstrated for toluene in liquid phase. A learning-loop optimal control scheme was applied to a stimulated Raman excitation process. Modifications of the phase shape of one of the exciting pulses resulted in dramatic changes of the mode distribution reflected in coherent anti-Stokes Raman spectra. An evolutionary algorithm guided the coherent excitation process to a selective enhancement or suppression of one or more vibrational modes over the complete coherence lifetime spanning several picoseconds. New ways of spectral filtering as well as exciting possibilities of mode-selective studying of chemical reaction dynamics are indicated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Feedback
  • Lasers*
  • Sensitivity and Specificity
  • Spectrum Analysis, Raman / methods
  • Time Factors
  • Toluene / chemistry*
  • Toluene / radiation effects

Substances

  • Toluene