114 research outputs found
Transformation optics in orthogonal coordinates
The author proposes the methodology of transformation optics in orthogonal
coordinates to obtain the material parameters of the transformation media from
the mapping in orthogonal coordinates. Several examples are given to show the
applications of such a methodology by using the full-wave simulations.Comment: 23 pages, 4 figure
Generalized laws of reflection and refraction from transformation optics
Based on transformation optics, we introduce another set of generalized laws
of reflection and refraction (differs from that of [Science 334, 333 (2011)]),
through which a transformation media slab is derived as a meta-surface,
producing anomalous reflection and refraction for all polarizations of incident
light.Comment: 7 pages, 3 figure
Time delays and energy transport velocities in three dimensional ideal cloaking
We obtained the energy transport velocity distribution for a three
dimensional ideal cloak explicitly. Near the operation frequency, the energy
transport velocity has rather peculiar distribution. The velocity along a line
joining the origin of the cloak is a constant, while the velocity approaches
zero at the inner boundary of the cloak. A ray pointing right into the origin
of the cloak will experience abrupt changes of velocities when it impinges on
the inner surface of the cloak. This peculiar distribution causes infinite time
delays for the ideal cloak within a geometric optics description.Comment: A scaling factor is added to convert the parameter \tau into the
physical tim
Non-Euclidean cloaking for light waves
Non-Euclidean geometry combined with transformation optics has recently led
to the proposal of an invisibility cloak that avoids optical singularities and
therefore can work, in principle, in a broad band of the spectrum [U. Leonhardt
and T. Tyc, Science 323, 110 (2009)]. Such a cloak is perfect in the limit of
geometrical optics, but not in wave optics. Here we analyze, both analytically
and numerically, full wave propagation in non-Euclidean cloaking. We show that
the cloaking device performs remarkably well even in a regime beyond
geometrical optics where the device is comparable in size with the wavelength.
In particular, the cloak is nearly perfect for a spectrum of frequencies that
are related to spherical harmonics. We also show that for increasing wavenumber
the device works increasingly better, approaching perfect behavior in the limit
of geometrical optics
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