Darmstadt 2008 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 15: Experimentelle Techniken
MO 15.1: Vortrag
Donnerstag, 13. März 2008, 11:00–11:15, 3G
Epi-Detected Multiplex CARS Microscopy — •Anke Horneber, Bernhard von Vacano, Christoph Pohling, and Marcus Motzkus — Physikalische Chemie, Philipps-Universität Marburg, D-35032
Chemically highly sensitive Coherent anti-Strokes Raman Scattering (CARS) spectroscopy can be achieved with a broadband multiplex technique. A single femtosecond laser source produces a narrow pump and probe pulse as well as a broadband Stokes pulse in a photonic crystal fibre. Multiplex CARS allows rapid recording of complete spectra within a vibrational range of more than 2000 cm−1. Using the spectral fingerprint of materials this sensitive method distinguishes clearly between chemically different samples. [1] In our new implementation the generated M-CARS signal is detected in backward direction (Epi) [2], spectrally resolved (better than 60 cm−1) and separated from the exciting laser light by an optimized steep edge bandpass filter. Detection in backwards direction allows mapping of non-transparent samples. It also promises higher three-dimensional spatial resolution and suppression of non-resonant background of bulk solvents. This technique has been successfully applied to map and identify different samples including polymers.
[1] B. von Vacano, L. Meyer, M. Motzkus, J. Raman Spectroscopy 38, 916 (2007).
[2] J. Cheng, A. Volkmer, L. D. Book, X. S. Xie, J. Phys. Chem. B 105, 1277 (2001).