Darmstadt 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MO: Fachverband Molekülphysik
MO 4: Femtosekundenspektroskopie II
MO 4.3: Vortrag
Montag, 10. März 2008, 17:00–17:15, 3G
Molecular sensing with a fibre laser using interferometric nonlinear vibrational spectroscopy — •Bernhard von Vacano, Jean Rehbinder, Tiago Buckup, and Marcus Motzkus — Physikalische Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse, D-35043 Marburg, Germany
Compact fs-fibre lasers promise to make nonlinear spectroscopy available for real-life applications. In a simple scheme, we demonstrate nonlinear vibrational spectroscopy with a single beam of femtosecond pulses from an unamplified fibre laser oscillator. To achieve high spectral resolution and sensitive signal detection with only picojoule pulse energies available, pulse shaping and integrated interferometric detection is employed. The spectroscopic technique used is coherent anti-Stokes Raman scattering (CARS), obtaining well-resolved spectra of molecular vibrations of halomethane samples in the liquid phase, covering 100 - 350cm−1. We explore the implications of phase control for the interferometric detection of weak signals. The presented combination of fiber laser, pulse shaping and CARS microspectroscopy is a first example of simplified schemes for compact and robust nonlinear spectroscopic detection and sensing, which is demonstrated exemplarily by online monitoring the chemical composition in a microfludic flow cell.