Relation of vectorial structures of diffracted plane waves with the elliptical aperture configuration and the light polarization in the far field

The analytical vectorial structure of a linearly polarized plane wave diffracted by an elliptical aperture is studied in detail based on the vector angular spectrum representation. It is found that the energy flux density spot sizes and the energy fluxes of the TE and TM term depend on the elliptical aperture configuration and the polarization direction of the incident plane wave. And the far fields can have smaller spots and larger energy fluxes for an elliptical aperture compared to a circular aperture with the same input wave amplitude. And its potential application in information encoding and transmission for free space communications is proposed apart from re-focusing to enhance the optical storage density. This encoding scheme has the benefit of easy implementation without modulating any properties of the light source.