# Slit¶

This example computes light propagation of incident plane waves (at oblique angle of incidence) through an isolated slit:

Note

Since the geometry of this setup exhibits two mirror symmetries you can reduce the computational domain to a quarter domain (at higher numerical efficiency). This is shown in section Exploiting Mirror Symmetry.

In a first post process, the Fourier transform for the upper half space is computed (output file `transmitted_fourier_transform.jcm`

). In a subsequent post-process `OpticalImaging`

this Fourier transform is mapped to `image_fourier_transform.jcm`

modelling the light transfer through the optical system (as defined in the post-process `OpticalImaging`

). You can use a Cartesian export post-process to compute the so formed coherent image. The following figure shows the image in different -slices (image planes displaced along -direction), for -polarized illumination.