Distinguished Seminar Series "Plasmonics: dealing
with loss" by Dr. Jacob Khurgin
Friday, November 01, 2013 12:00 PM to 1:00 PM
CREOL Room 102
CREOL Room 102
Jacob Khurgin
Professor- Dept of Electrical and Computer Engrg
Johns Hopkins University
Abstract:
Recent years have seen staggering growth of interest in
using nanostructured metals in optical range with the goal of enhancing linear
and nonlinear optical properties or even engineering novel optical properties
unknown in Nature – usually this burgeoning field is referred to as “Plasmonics
and Metamaterials”. After the initial years of excitement the community
is belatedly beginning to recognize that loss in the metal is an important
factor that might impede practical application of plasmonic devices, be it in
signal processing, sensing, imaging or more esoteric applications like
cloaking. Yet there is still an optimism that the loss can be either cleverly
“designed away”, compensated by gain, or a new lossless materials can be found.
In this talk we examine these concepts one by one and find that they all have
limitations. First we show that when it comes to enhancing the device
performance (solar cells, sensors, nonlinear optical devices, etc.) only the
most inefficient devices can be improved by plasmonics while the performance of
any decent device will only degrade. Then we demonstrate that in truly
sub-wavelength metal structures the metal loss is inherent and cannot be
engineered away by crafty changes in shape. Graphene as an alternative
plasmonic material will also be considered and found to fall well short of
being a universal cure for plasmonic ills. We then consider the idea of
compensating loss using semiconductor gain medium and demonstrate that required
gain can never be achieved due to increase in recombination rates caused by
Purcell effect. After that we consider the physics of losses in metals at
optical frequencies and show that the nature of these losses is quite different
from the losses in RF domain. We then show that negative dielectric constant at
optical frequencies does not have to inevitably lead to large absorption, and
guardedly point to the tentative way in which new materials with negative
dielectric constant and very low loss might be synthesized, thus restoring
the faint hope for plasmonics.
Biography:
Jacob B. Khurgin had graduated with MS in Optics from the
Institute of Fine Mechanics and Optics in St Petersburg, Russia in 1979, where,
naturally, he was had been earlier born. In 1980 he had emigrated to US, and,
to his own great surprise, immediately landed what at a time seemed to be a
meaningful job with Philips Laboratories of NV Philips in Briarcliff Manor, NY.
There for 8 years he worked with various degrees of success on miniature
solid-state lasers, II-VI semiconductor lasers, various display and lighting
fixtures, X-ray imaging, and small appliances such as electric shavers and
coffeemakers (for which he holds 3 patents). Simultaneously he was pursuing his
graduate studies at Polytechnic Institute of NY (nowadays NYU School of
Engineering) where he had received PhD in Electro-physics in Jan. 1987. In Jan.
1988, prompted by a promotion to a Department Manager, Khurgin’s industrial
career came to an abrupt end, and he had joined the Electrical and Computer
engineering department of Johns Hopkins University, where, despite his ever
present reservations about that place, he had settled down and is currently a
Professor. His research topics over the years included an eclectic
mixture of optics of semiconductor nanostructures, nonlinear optical devices,
lasers, optical communications, microwave photonics, and condensed matter
physics. Currently he is working in the areas of mid-infrared lasers and
detectors, phonon engineering for high frequency transistors, disorder in
condensed matter physics, plasmonics, coherent secure optical communications,
silicon photonics, cavity optomechanics, and slow light propagation. His
publications include 6 book chapters, one book edited, 240 papers in refereed
journals and 28 patents. Prof Khurgin had held a position of a Visiting
Professor in an array of institutions of variable degrees of repute –
Princeton, UCLA, Brown, Ecole Normale Superieure (Paris), Ecole Polytechnique
(Paris) and so on. Prof. Khurgin is a Fellow of American Physical Society and
Optical Society of America.
For additional information:
Dr. Demetrios Christodoulides
Professor of Optics
407-882-0074
demetri @ creol . ucf . edu
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