Researchers
at the University of Pennsylvania propose to shrink
circuits in order to save space and power and, more
importantly, to accommodate electronic applications
at much higher frequencies than are possible with
current models, applications that include nano-optics,
optical information storage, and molecular signaling.
Electric circuit elements, among them resistors,
capacitors, and inductors, come in a variety of sizes
to deal with a variety of applications at a range
of frequencies. The familiar electrical grid, for
example, operates at a frequency of 60 Hz. A circuit
designed to process radio signals operates at the
100-megahertz range. A typical frequency domain for
computers is 1 GHz. Higher still, microwave applications
often operate at the 10-GHz (10 10 Hz) level.
Nader Engheta (engheta@ee.upenn.edu, 215-898-9777)
and his Penn group would like to extend the circuit
concepts up to optical frequencies, around 10 15
Hz. To do this, instead of just shrinking the classic
circuit elements to fraction of the typical wavelength
of the optical signal being processed (around 500
nm), the Penn proposal is to make nano-inductors,
nano-capacitors and nano-resistors out of sub-wavelength
nano-particles, fashioned from appropriate materials
on a substrate with lithographic techniques. Possible
applications would include direct processing of optical
signals with nano-antennas, nano-circuit-filters,
nano-waveguides, nano-resonators, and even nano-scaled
negative-index optical structures. (Engheta et
al. , Physical Review Letters, upcoming article; http://www.ee.upenn.edu/~engheta/ )
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