Marsh, RJ;
Leonczek, ND;
Armoogum, DA;
Porres, L;
Mongin, O;
Blanchard-Desce, M;
Bain, AJ;
(2004)
Stimulated emission depletion dynamics in push-push polyenes.
In: Andrew, DL and Cao, GZ and Gaburro, Z, (eds.)
Nanophotonic Materials.
Society of Photo-Optical Instrumentation Engineers (SPIE): Denver, CO, USA.
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Abstract
Two-photon fluorescence polarisation and stimulated emission depletion dynamics are investigated in three high two -photon cross-section push-push polyenes: OM62, LP79 and OM77 and compared to the behaviour of a standard fluorophore (rhodamine 6G). Two-photon fluorescence anisotropy measurements (R(O) and Omega) were undertaken using picosecond time-correlated single photon counting (TCSPC). For OM62 and LP79 these are consistent with a diagonal two-dimensional transition tensor with S-XX>S-YY. For OM77 the contribution of off-diagonal elements (S-XY & S-YX) appears significant. Two-photon fluorescence anisotropy decay data is combined with streak camera measurements of excited state population depletion to determine stimulated emission cross sections and ground state vibrational relaxation times. Cross-sections for STED in all three polyenes were found to be significantly higher than those for rhodamine 6G. The efficiency of STED is however dependent on the degree to which the S-1-->S-0 transition is saturated by the DUMP pulse; this is mediated by fast ground state vibrational relaxation. Of the three polyenes.. LP79 is seen to combine a large stimulated emission cross-section (c.a. 13sigma(r6G)) with rapid ground state relaxation (tau(R)=240fs).
| Type: | Proceedings paper |
|---|---|
| Title: | Stimulated emission depletion dynamics in push-push polyenes |
| Event: | Nanophotonic Materials |
| Location: | Denver, CO |
| Dates: | 02 August 2004 - 03 August 2004 |
| ISBN: | 0819454486 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1117/12.564433 |
| Publisher version: | http://dx.doi.org/10.1117/12.564433 |
| Language: | English |
| Additional information: | Copyright © 2004 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: | two-photon absorption, stimulated emission depletion, fluorescence anisotropy, polarisation vibrational relaxation, 2-photon absorption, quadrupolar chromophores, fluorescence anisotropy, imaging microscopy, pull dipolar, fluorophores, spectroscopy, molecules, states, derivatives |
| 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/36159 |
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