This package can be used for simulations of scalar and vectorial vortex beams, focused with an arbitrary numerical aperture and propagating through a three-layered system. Propagation is simulated at normal incidence, with respect to the interfaces in-between the media. Every layer can describe an isotropic lossy material by a choice of its permittivity and permeability; layer 2 allows for anisotropy. In the latter case, the anisotropic crystal is intended to be uniaxial, with its optical axis oriented along the propagation direction (z), so that the permittivity tensor is given by diag(eps_x, eps_x, eps_z). For more detailed information, open the README.txt file and check the help added at the beginning of each file.