Symmetry and resonant modes in platonic grating stacks

Symmetry Groups of Platonic Solids

'Parabolic' trapped modes and steered Dirac cones in platonic crystals.

This paper discusses the properties of flexural waves governed by the biharmonic operator, and propagating in a thin plate pinned at doubly periodic sets of points. The emphases are on the design of dispersion surfaces having the Dirac cone topology, and on the related topic of trapped modes in plates for a finite set (cluster) of pinned points. The Dirac cone topologies we exhibit have at leas...

Defect grating modes as superimposed grating states

Grating structures are often used in integrated optical devices and in sensor applications. A defect grating structure as will be considered here has defect modes with full transmission at a specific (defect) wavelength in the bandgap of the gratings. See e.g. [2] for bandgap in gratings, and [3, 4] for gratings as one-dimensional versions of photonic bandgap materials or photonic crystals; a F...

Resonant Modes and Resonant Transmission in Multi-layer Structures

Resonant modes of multi-layer structures which contain the regions of negative epsilon material (such as a metal in the visible range) are analyzed. Existence of two separate classes of resonant modes is demonstrated. One is related to the excitation of the surface mode at the interface of the regions with opposite signs of the dielectric constant and involve energy transport by evanescent mode...

Resonant driving and k-symmetry

A particular type of`resonant' periodic driving of a symmetric dynamical system may cause the time-one map of the driven system to have a non-trivial root that possesses less symmetry than the time-one map itself. The latter phenomenon is called k-symmetry. Some examples and consequences to the dynamical behaviour are pointed out brieey.