Control of CO2 vibrational dynamics via shaped-pulse Coherent Anti-Stokes Raman Spectroscopy
Presented by Mr. Attie HENDRIKS on 8 Jul 2014 from 11:50 to 12:10
Type: Oral Presentation
Track: Track C - Photonics
We investigate control of the vibrational dynamics of CO2 molecules in gas phase using Coherent Anti-stokes Raman Scattering (CARS). During CARS, a pump and Stokes pulse excite a vibrational mode via a Raman process. This is followed by a probe pulse which indicates the extent of mode occupation through Anti-Stokes fluorescence. In our experiment we simultaneously excite the bend and stretch modes of CO2, and observe coherent temporal oscillations in the Anti-Stokes signal, at the beat-note of the two modes. Using a learning algorithm we execute time-frequency shaping of the pump pulses in our CARS experiment. This provides selective excitation between the stretch and bend modes. We compare the experimental outcomes to a perturbative model that simulates the nonlinear dynamics.
Hermann Uys HUys@csir.co.za