189 research outputs found
Giant In-Particle Field Concentration and Fano Resonances at Light Scattering by High-Refractive Index Particles
A detailed analytical inspection of light scattering by a particle with high
refractive index m+i\kappa and small dissipative constant \kappa is presented.
We have shown that there is a dramatic difference in the behavior of the
electromagnetic field within the particle (inner problem) and the scattered
field outside it (outer problem). With an increase in m at fix values of the
other parameters, the field within the particle asymptotically converges to a
periodic function of m. The electric and magnetic type Mie resonances of
different orders overlap substantially. It may lead to a giant concentration of
the electromagnetic energy within the particle. At the same time, we
demonstrate that identical transformations of the solution for the outer
problem allow to present each partial scattered wave as a sum of two
partitions. One of them corresponds to the m-independent wave, scattered by a
perfectly reflecting particle and plays the role of a background, while the
other is associated with the excitation of a sharply-m-dependent resonant Mie
mode. The interference of the partitions brings about a typical asymmetric Fano
profile. The explicit expressions for the parameters of the Fano profile have
been obtained "from the first principles" without any additional assumptions
and/or fitting. In contrast to the inner problem, at an increase in m the
resonant modes of the outer problem die out, and the scattered field converges
to the universal, m-independent profile of the perfectly reflecting sphere.
Numerical estimates of the discussed effects for a gallium phosphide particle
are presented.Comment: 18 pages, 10 figure
Effect of Energy Conservation Law, Space Dimension, and Problem Symmetry on the Poynting Vector Field Singularities
A brief review is given of the author recent achievements in classifying
singular points of the Poynting vector patterns in electromagnetic fields of
complex configuration. The deep connection between the topological structure of
the force lines pattern and the law of energy conservation, the symmetry of the
problem, and the dimension of the space has been unveiledComment: 12 pages, 8 figure
Nonlinear Pattern Selection in Binary Mixture Convection with Through-Flow
The pattern selection problem in binary-mixture convection in an extended
channel with a lateral through-flow is presented. The through-flow breaks
left--right parity and changes pattern dynamics dramatically. The problem is
studied based on computer simulation of the complete set of hydrodynamic
equations (Oberbeck-Boussinesq approximation) in the two-dimensional
rectangular channel with aspect ratio and convection-suppressing
lateral boundary conditions. A wide variety of new dynamical patterns is
obtained, discussed and classified.Comment: 9 pages and 2 figure
Giant field enhancement in high-index dielectric subwavelength particles
Besides purely academic interest, giant field enhancement within
subwavelength particles at light scattering of a plane electromagnetic wave is
important for numerous applications ranging from telecommunications to medicine
and biology. In this paper, we experimentally demonstrate the enhancement of
the intensity of the magnetic field in a high-index dielectric cylinder at the
proximity of the dipolar Mie resonances by more than two orders of magnitude
for both the TE and TM polarizations of the incident wave. We present a
complete theoretical explanation of the effect and show that the phenomenon is
very general - it should be observed for any high-index particles. The results
explain the huge enhancement of nonlinear effects observed recently in optics,
suggesting a new landscape for all-dielectric nonlinear nanoscale photonics.Comment: 8 pages, 4 figure
- …