Marsh, RJ;
Leonczek, ND;
Armoogum, DA;
Monge, EM;
Bain, AJ;
(2005)
Stimulated emission depletion studies of molecular probe dynamics.
In: Gaburro, Z and Cabrini, S, (eds.)
Nanophotonic Materials and Systems II.
Society of Photo-Optical Instrumentation Engineers (SPIE): San Diego, CA, USA.
Preview |
Text
Bain_59250C_1_STED study of probe dynamics.pdf Download (356kB) | Preview |
Abstract
Stimulated emission depletion (STED) population and polarisation dynamics are used to determine (α40 the degree of hexadecapole alignment created in ensembles of rhodamine 6G molecules in solution following two-photon excitation. Hexadccapolo molecular alignment is an unavoidable consequence of two-photon excitation but is not observed in spontaneous emission. For a single element diagonal transition tensor measurements of the fluorescence anisotropy R(t) in systems undergoing small step isotropic rotational diffusion can in principle be used to determine (a40)- STED measurements of rhodamine 6G yield a value for (α40) tnat is larSer tnan tnat predicted for a single element transition tensor (Sxx). Recent work in our laboratory indicates that whilst Sxx is dominant Syy, Sxy and Syx are finite, measurements of (α40} appear to be a sensitive probe of the structure of the two-photon transition tensor. STED and fluorescence anisotropy measurements are extended to Rhodamine 6G in the isotropic phase of 5CB a system where small step Isotropie rotational relaxation does not take place. Here the values of 〈α40〉 are considerably larger. These results are discussed in terms of the initial hexadecapole alignment and 〈α40〉 relaxation dynamics in a restricted geometry.
| Type: | Proceedings paper |
|---|---|
| Title: | Stimulated emission depletion studies of molecular probe dynamics |
| Event: | Nanophotonic Materials and Systems II |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1117/12.634088 |
| Publisher version: | http://dx.doi.org/10.1117/12.634088 |
| Language: | English |
| Additional information: | Copyright © 2005 Society of Photo Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. |
| Keywords: | Molecular alignment, Polarisation, Stimulated emission depletion, Transition tensor, Two-photon fluorescence |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/39090 |
Archive Staff Only
 |
View Item |
