| Autor: |
Kim, Hyung Min, Kim, Hyunmin, Yang, Ilseung, Jin, Seung Min, Suh, Yung Doug |
| Zdroj: |
Physical Chemistry Chemical Physics (PCCP); 2014, Vol. 16 Issue 11, p5312-5318, 7p |
| Abstrakt: |
We present time-gated femtosecond stimulated Raman spectroscopy (fSRS) under the pre-resonance Raman conditions of diethylthiatricarbocyanine (DTTC) iodide. A ‘pseudo emission-free’ condition is achieved by delivering the probe beam ahead of the pump beam. Regeneratively amplified pulse trains are employed to create an angle-geometry (non-collimated) mixing between the pump and probe beams, leading to highly sensitive measurement of the stimulated Raman gain. Time-integrated spectroscopy allows for a more quantitative distinction between the contributions of stimulated Raman scattering and stimulated emission. We successfully obtain a highly sensitive (signal-to-noise ratio ＞100) stimulated Raman spectrum under the optimized conditions, which compares favourably to results obtained using two-dimensional correlation spectroscopy (2DCOS). Given the optical pre-resonance of ∼0.1 eV, the background signals mostly originate from the stimulated emission of excited electrons and are significantly reduced by partial overlapping of the pump and probe beams; a genuine fSRS spectral profile is obtained for a temporal delay of ∼0.2 ps between the two beams. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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