Nano-optics with single quantum systems.
This paper reviews the recent progress in using single quantum systems, here mainly single fluorescent molecules, as local probes for nano-optical field distributions. We start by discussing the role of the absorption cross-section for the spatial resolution attainable in such experiments and its behaviour for different environmental conditions. It is shown that the spatial distribution of field components in a high-numerical aperture laser focus can be mapped with high precision using single fluorescent molecules embedded in a thin polymer film on glass. With this proof-of-principle experiment as a starting point, the possibility of mapping strongly confined and enhanced nano-optical fields close to material structures, e.g. sharp metal tips, is discussed. The mapping of the spatial distribution of the enhanced field at an etched gold tip using a single molecule is presented as an example. Energy transfer effects and quenching are identified as possible artefacts in this context. Finally, it is demonstrated that the local quenching at a sharp metal structure nevertheless can be exploited as a novel contrast mechanism for ultrahigh-resolution optical microscopy with single-molecule sensitivity.
NCCR Nanoscience, Nano-Optics Group, Institute of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
Bert
B
Hecht
D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000295:instrumentation / Q000379:methods*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D055095:Optics and Photonics / Q000295:instrumentation; D045663:Quantum Dots