Stuttgart 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MO: Fachverband Molekülphysik
MO 1: Vibrational Spectroscopy
MO 1.1: Hauptvortrag
Montag, 12. März 2012, 10:30–11:00, V38.03
Vibrational Molecular Interferometry — •Herman L Offerhaus1, Erik T Garbacik1, Shaul Mukamel2, Alexander CW van Rhijn1, Cees Otto3, and Jennifer L Herek1 — 1Optical Sciences group, University of Twente, the Netherlands — 2Department of Chemistry, University of California, Irvine, USA — 3Medical Cell BioPhysics group, University of Twente,
We demonstrate an implementation of a CARS microscopy method that is based on an interaction picture centered on the molecules, as proposed in [1], rather than the interacting fields. It provides an intuitive and unified description of the various signal contributions, allowing easy extraction of the vibrational response. Three optical fields create a pair of Stokes Raman pathways that interfere in a single vibrational state. Frequency modulating two of the fields leads to amplitude modulations of the signals, which we refer to as vibrational molecular interferometry (VMI). The modulation depth that we observe is comparable to that found in SRS, and allows imaging at high speed free of the non-resonant background that plagues coherent anti-Stokes Raman scattering (CARS) measurements. The demonstration is on a narrowband system and does not offer a large improvement in practical terms over existing SRS strategies, except that it can distinguish between electronic and vibrational transitions and avoids signals from Kerr-lensing. The new strategy is not limited to narrowband CARS and broadband extensions are possible. [1] Rahav, S. & Mukamel, PNAS 107, 4825-4829,(2010).