NormalShift¶

Type:	float
Range:	[-inf, inf]
Default:	0.0
Appearance:	simple

With the notation and the coordinate convention of the parent section, the Fourier transform of the upward directed electromagnetic field on the xy plane with $z$ position above the scatterer is given by

$\begin{eqnarray*} \VField{E}_{\uparrow}^{\wedge}(\pvec{k}_\perp, z) = \VField{E}_{\uparrow}^{\wedge}(\pvec{k}_\perp)e^{ik_z z}. \end{eqnarray*}$

As default, the $z$ independent expression $\VField{E}_{\uparrow}^{\wedge}(\pvec{k}_\perp)$ is computed. One may regard this as the Fourier transform at $z=0$ . However, this is questionable when the scatterer extends into the upper half space $z>0$ , since then it is not possible to extract the upward directed field on the $z=0$ plane.

To get $\VField{E}_{\uparrow}^{\wedge}(\pvec{k}_\perp, z)$ as above set the normal shift to the desired $z$ -value.