Hamburg 2009 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 5: Quantenkontrolle 1

MO 5.1: Vortrag

Montag, 2. März 2009, 14:00–14:15, VMP 6 HS-G

Optimization and application of heterodyne single-beam CARS microscopy — •Christina Müller¹, Tiago Buckup¹, Bernhard von Vacano², and Marcus Motzkus¹ — ¹Physikalische Chemie, Philipps-Universität Marburg, D-35032 Marburg, Germany — ²Polymer Physics, BASF SE, D-67056 Ludwigshafen, Germany

Single-beam coherent anti-Stokes spectroscopy presents a unique and powerful approach to nonlinear microscopy since a complete CARS scheme is accomplished using just a tailored pulse from a fs-oscillator and coherent control of the non-linear signal generation by phase modulation of the excitation with a pulse shaper.[1] In a previous work, we have demonstrated that even a heterodyne detection scheme with an additional local oscillator can be implemented in the single-beam approach by pulse shaping.[2, 3] In this contribution, we present and compare two different approaches of modulating heterodyne signal for sensitive-lock-in detection. We show the careful optimisation of the experimental scheme analysing the different relations between local oscillator field and CARS signal intensity in order to improve the sensitivity of the method. After successful optimization the scheme is introduced to microscopic applications, combining chemical selectivity and a high spatial resolution of non-linear CARS processes with the sensitivity to low sample concentrations.
N. Dudovich, D. Oron, Y. Silberberg, Nature 418, 512 (2002).
B. von Vacano, T. Buckup, M. Motzkus, Opt. Lett. 31, 2495 (2006).
B. von Vacano, J. Rehbinder, T. Buckup, M. Motzkus, Appl. Phys. B 91, 213 (2008).