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Published on: November 3, 2009
Absorption and fluorescence of single molecules.
J Y P Butter1, B Hecht, B R Crenshaw
1Nano-Optics Group, National Center of Competence for Research in Nanoscale Science, Institute of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel, Switzerland.
The Journal of Chemical Physics
|October 25, 2006
Summary
This study demonstrates simultaneous absorption and fluorescence detection of single molecules at cryogenic temperatures. It reveals dynamical processes and highlights molecules with strong absorption but minimal fluorescence emission.
Area of Science:
- Single-molecule spectroscopy
- Quantum optics
- Cryogenic physics
Background:
- Understanding single-molecule behavior is crucial for quantum information and materials science.
- Confocal microscopy is a powerful tool for probing nanoscale phenomena.
- Cryogenic temperatures minimize thermal noise, enabling sensitive measurements.
Purpose of the Study:
- To demonstrate simultaneous absorption and fluorescence detection of single molecules.
- To investigate dynamical processes like blinking and spectral jumping.
- To correlate absorption and fluorescence properties and understand underlying mechanisms.
Main Methods:
- Utilizing confocal microscopy at cryogenic temperatures.
- Simultaneously measuring absorption and fluorescence signals from single molecules.
- Analyzing blinking, spectral jumping, linewidth, and amplitude variations.
Main Results:
- Simultaneous absorption and fluorescence detection of single molecules achieved.
- Observed dynamical processes including blinking and spectral jumping in both channels.
- Found variations in fluorescence-to-absorption ratios, with some molecules showing strong absorption but no detectable fluorescence.
- Demonstrated that coherent resonant scattering underlies absorption, evidenced by linewidth-amplitude correlation.
Conclusions:
- Simultaneous detection provides a more comprehensive view of single-molecule properties.
- The observed phenomena offer insights into light-matter interactions at the single-molecule level.
- Coherent resonant scattering is a key factor in absorption processes for certain single molecules.
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