title: Diffracted electromagnetic fields in the neighborhood of the focus of a paraboloidal mirror having a central obscuration.
abstract: The structure of the diffracted electromagnetic field generated by a paraboloidal mirror having a possible central obscuration without wavefront aberrations, but allowing for defocus, is studied. Particular attention has been paid to the time average electric energy density; numerical results are displayed for various azimuthal lines. Contour plots are shown; as expected they are not rotationally symmetric. Finally, we introduce and numerically evaluate the encircled time average electric energy density. In conformity with the investigations of Yoshida and Asakura on the corresponding problem of an aplanatic optical system with central obscuration, the structure of the diffracted electromagnetic field is very dependent on the amount of obscuration.
authors.forename: R
authors.initials: R
authors.lastname: Barakat