Plasmonics Biographic Information
“Sub-wavelength imaging in mid-infrared: from
superlensing to plasmonic endoscopes”
Gennady Shvets
Associate Professor of Physics, University of Texas at
Austin
Abstract
Mid-infrared is one of the most important segments of
the optical spectrum because it contains the "fingerprints" of most
biological molecules. An explosion of near-field techniques (e.g.,
spectroscopy with sub-cellular resolution, labels-free detection)
motivates the development of new sub-wavelength imaging tools.
Experimental demonstration of a near-field super-lens in the mid-infrared
(around 11 microns) range will be described. The lens is implemented using
crystalline SiC films that have remarkable infrared properties: they
support surface polaritons with less damping than most metals. Two
demonstrations of super-lensing with l/20 spatial
resolution will be demonstrated: (a) using FTIR microscopy [1], and (b) by
direct near-field probing with NSOM [2]. Both amplitude and
phase-sensitive imaging is demonstrated. It is also demonstrated that
super-lensing can be used for sub-surface imaging. Applications to
biologically-relevant imaging through water in nanofluidic channels will
be discussed. In the second half of the talk, I will describe a novel
imaging tool in IR/THZ: tapered multi-wire coaxial endoscope. Using a
conventional coaxial waveguide (the ultimate sub-wavelength element!) as
an inspiration, I will demonstrate how two types of nanoscale imaging
applications are enabled: image magnification and radiation focusing. In
the first scenario, the tapered wire array acts as a multi-pixel TEM
endoscope by capturing a detailed electromagnetic field profile created by
deeply sub-wavelength objects at the endoscope's tip and magnifying it for
observation. The resulting imaging method is
superior to the conventional scanning microscopy because
of the parallel nature of the image acquisition by multiple metal wires.
In the second scenario, the image of a large mask at the
endoscope's base can be projected into a much smaller
image at the tip, paving the way to novel lithographic techniques.
Bio.
Gennady Shvets is an Associate Professor of Physics at
The University of Texas at Austin. He received his PhD in Physics from MIT
in 1995. He has been on the Physics faculty at the University of Texas at
Austin since 2004. Previously he has held research positions at the
Princeton Plasma Physics Laboratory and the Fermi National Accelerator
Laboratory, and was on the faculty of the Illinois Institute of
Technology. His research interests include nano-photonics, meta-materials
with exotic optical properties (especially negative index), near field
optics, laser processing of materials on a nanoscale, and advanced
particle accelerators. Dr. Shvets was a Department of Energy Postdoctoral
Fellow in 1995-96. He was a recipient of the Presidential Early Career
Award for Scientists and Engineers in 2000. His research is supported by
DOE, NSF, DARPA, AFOSR, and ARO.