idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
Abstract: Fluorescence lifetimes can be measured with a cw laser which is modulated in the MHz range. The fluorescence emission is also modulated but, due to the non-zero lifetime, features a phase shift and a reduced modulation amplitude as compared to the excitation. This behavior is analogous to the transfer function of an electronic low-pass filter and can be described with very similar equations. The fluorescence lifetimes calculated from the phase shift and the modulation amplitude are identical in the case of single-exponential fluorescence decay and differ otherwise. For the interpretation of the data the so-called polar-plot (or phasor) approach is particularly useful which is equivalent to the Cole-Cole plot in dielectric spectroscopy. The distribution of data points corresponding to different spots on a sample allows one to assess and interpret material inhomogeneities. Experimental data and their polar plots will be presented for three different examples: The laser dye Rhodamine 6G doped into different polymer matrices, an auto-fluorescent conjugated polythiophene polymer, and the inorganic chalcogenide semiconductor gallium selenide (GaSe).
Information on participating / attending:
Interessierte sind herzlich eingeladen!
Kaffee ab 16:30 Uhr vor dem GSR.
Organisation: Prof. H. Fehske und Prof. L. Schweikhard
Institut für Physik, Felix-Hausdorff-Straße 6, 17489 Greifswald
Telefon 03834 86-4700, http://www.physik.uni-greifswald.de
Date:
06/25/2015 17:00 - 06/25/2015 18:30
Event venue:
Institut für Physik
Felix-Hausdorff-Straße 6
17489 Greifswald
Mecklenburg-Vorpommern
Germany
Target group:
Scientists and scholars, Students
Relevance:
transregional, national
Subject areas:
Physics / astronomy
Types of events:
Presentation / colloquium / lecture
Entry:
05/12/2015
Sender/author:
Sabine Köditz
Department:
Presse- und Informationsstelle
Event is free:
no
Language of the text:
German
URL of this event: http://idw-online.de/en/event50909
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