It is shown how to model the effect of unpolarized light in VirtualLab Fusion as the average of two orthogonal polarization states, using the simulation of grating systems as examples.

This system illustrates the function of a confocal microscope using a grating as a sample. With the thorough vectorial treatment of the electromagnetic field in VirtualLab Fusion alongside its “connecting field solvers” approach, the initial field polarization, the faint cross-talk at the lens surfaces, the appearance of the longitudinal component due to the focusing behind the objective, as well as the strongly vectorial response of the grating are all automatically taken into account in the simulation in a seamless way.