Optical frequency- and vibrational time-resolved two-dimensional spectroscopy by real-time impulsive resonant coherent Raman scattering in polydiacetylene
Abstract
Real-time impulsive resonant Raman scattering induced by a 4-fs ultrashort laser pulse was spectrally resolved with a multichannel lock-in amplifier. An optical and vibrational two-dimensional spectrum was introduced to separate the effects of electronic and vibrational broadening in the power spectrum of the vibrations. Spectrally resolved real-time oscillations can identify the wave packet motion associated with the stretching vibrational mode of the carbon-carbon double and triple bonds of the polymer polydiacetylene. Calculated nonlinear polarizations which take into account the ground-state wave packets reproduced the observed dynamics fairly well. It is confirmed that the ground-state vibrations play a significant role in the dynamics of the wave packet even far below the absorption edge, as well as the excited-state vibrations.
- Publication:
-
Physical Review A
- Pub Date:
- August 2004
- DOI:
- 10.1103/PhysRevA.70.023811
- Bibcode:
- 2004PhRvA..70b3811I
- Keywords:
-
- 42.65.Dr;
- 78.47.+p;
- 82.53.-k;
- Stimulated Raman scattering;
- CARS;
- Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter;
- Femtochemistry