The calculation of the electric field vectors is based on a rigorous, vectorial model that takes polarization effects in the near-focus region and high numerical aperture microscope objectives into account.

[1] The polarization of the input beam (assumed to be collimated and monochromatic) can be chosen freely (linear, circular, or elliptic).

Furthermore, a constant or Gaussian shaped input beam intensity profile can be assumed.

PSF Lab can also simulate microscope objectives that are corrected for certain refractive indices and cover slip thicknesses (design parameters).

Thus, any deviations from the ideal imaging conditions for which the objective was designed for are properly taken into account.