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Resonant Optical Antennas
Controlling the flow of light on the scale of few nanometers is of utmost importance for future
progress in nanoscience. Using well-designed metallic nano structures it is possible to locally
confine optical fields. High-resolution optical microscopy techniques based on this principle
allow us to determine the chemical composition of nanometerscale samples which are organized in
a nanoscale context. On the other hand nano-optical devices such as enhanced sources for single
photons on demand become conceivable which will have an impact on quantum information technology.
The Nano-Optics group in Basel has devised and developed a novel concept for optimising the
concentration of light. In analogy to the radio frequency domain antenna-type structures are
used. For suitable dimensions (half the wavelength ~250 nm) these structures efficiently collect
light and focus it to the so-called feed point of the antenna. In this tiny volume (20x20x20nm3)
extreme light intensities are created. Vice versa, the same structures can be applied to enhance
and direct the radiation of a single quantum emitter placed in the antenna’s feed point. Both
aspects of optical antennas have recently been demonstrated in Basel. The work is continued to
optimize the observed effects and to utilize them in devices.
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Figure: left: local intensity in resonant and off-resonant dipole antennas.
Scale bar 200 nm. Right: antenna structure at the apex of an atomic force
microscopy tip. |
Single Quantum Dot Coupled to a Scanning Optical Antenna: A Tunable Superemitter
J. N. Farahani, D. W. Pohl, H.-J. Eisler, and B. Hecht
Phys. Rev. Lett. 95, 017402 (2005)
Resonant Optical Antennas
P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, D. W. Pohl
Science, Vol 308, Issue 5728, 1607-1609 , 10 June 2005
Contact:
Bert Hecht |
Dieter Pohl |
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Institute of Physics
University of Basel
Switzerland |
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