GroupTheory`
GroupTheory`

GTPhPermittivityMatrix

GTPhPermittivityMatrix[reciprocal basis,cutoff,objects,background]

gives the complete matrix i.e. the Fourier transform of . The reciprocal lattice vectors are defined by the reciprocal basis and vectors with < cutoff for a structure in the unit cell defined by objects. The structure is embedded in a dielectric background.

Details and Options

  • Two methods of the construction of the master equation, i.e. the eigenvalue problem to calculate photonic band structures are possible. First, the Fourier transform of ϵ(r) is calculated on the fly during the construction of the eigenvalue problem, second the is calculated beforehand. GTPhPermittivityMatrix allows to calculate the matrix in two ways. First, it can be calculated directly by Fourier transform of epsilon^(-1)(r), the so called direct method. In the second method, so called Hos method (method of matrix inversion), the Fourier transform of ϵ(r) is calculated. The corresponding matrix is inverted.
  • The following options can be given:
  • GODCMethod "Direct"Method to calculate the matrix
    GOPixelFalseDecides the type of calculation: pixelmap or list of objects
    GOVerbose FalseControls the output of additional information
  • See: W. Hergert, M. Geilhufe, Group Theory in Solid State Physics and Photonics. Problem Solving with Mathematica, chapter 10.4
  • K. M. Ho, C. T. Chan, C. M. Soukulis, Existence of a Photonic Gap in Periodic Dielectric structures. Phys. Rev. Lett. 65, 3152 (1990).

Examples

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Basic Examples  (1)

First load the package:

As an example dielectric rods in a square lattice in air are considered. The structure is defined:

The Fourier transform of is calculated.

The eigenvalue problem is constructed for the TM polarization.

The path in the Brillouin zone is fixed.

The band structure is calculated and plotted.

Options  (2)

GODCMethod  (1)

The Fourier transform of is calculated and the corresponding matrix is inverted afterwards.

Both methods lead to the same photonic band structures. The small differences occur due to the limited number of plane waves used in the calculations.

GOVerbose  (1)

Additional information can be obtained.