ConvertToPowerFlux¶

Type:	section
Appearance:	simple
Excludes:	CartesianToFourierTransform, CreateReducedBasis, DensityIntegration, DipoleEmission, EvaluateReducedBasis, ExportFields, ExportGrid, FarField, FluxIntegration, FourierTransform, GridStatistics, IntegrationWeights, LayeredMediaSolver, ModeOverlap, MultipoleExpansion, OpticalImaging, PupilField, Radiation, ResonanceExpansion, ResonanceOverlap, ScatteringMatrix, Superposition, SurfaceDensityIntegration

This PostProcess converts the output of the FourierTransform of a field stored in JCM table to the corresponding ElectromagneticFieldEnergyFluxDensity table. Its output can be used to replace the corresponding functions ‘convert2powerflux’ to compute the Poynting-Vector from a set of plane waves.

In the input Fourier transform table, each row corresponds to an electric plane wave $\VField{E}(\pvec{k})\exp(i\pvec{k}\cdot\pvec{r})$ and a magnetic plane wave $\VField{H}(\pvec{k})\exp(i\pvec{k}\cdot\pvec{r})$ . In the output file the ElectromagneticFieldEnergyFluxDensity is formed as

$\begin{eqnarray*} \VField{S}(\pvec{k}) = \frac{1}{2}\VField{E}(\pvec{k})\times \VField{H}(\pvec{k})^\ast \end{eqnarray*}$

Note

One may want to use ConvertToPowerFlux when derivatives are included. These are not transformed by the scripting functions.

Warning

While the output of continuous spectra by the FourierTransform post-process are handled identically to periodic ones, the resulting spectrum does not correspond to the flux of the field when integrated over the normal component.

Storage format

The computed Fourier transform is stored in a JCM table under the path OutputFileName. Each row in the table corresponds to a plane wave with angular wave number $\pvec{k}_j$ stored in the first the columns. Summing up (superimposing) these plane waves gives an approximation of the upward directed field:

The output JCM table file has the following columns:

Columns 1 … 3*N: ElectromagneticFieldEnergyFluxDensityX_<iF>, ElectromagneticFieldEnergyFluxDensityY_<iF>, ElectromagneticFieldEnergyFluxDensityZ_<iF>,

The index <iF> stands for the field index. The $x$ , $y$ , and $z$ components of one field are stored in consecutive columns.