Nonparaxial fields with maximum joint spatial-directional localization. II. Vectorial case.
The monochromatic nonparaxial vector fields that achieve a minimum spatial spread for a given directional spread are found. The derivation of these fields is analogous to the one presented in part I of this series for the case of scalar fields. This derivation is based on a variational treatment and multipolar expansion. The resulting lower bounds for the spreads of vector fields turn out to be considerably more restrictive than for scalar fields.
The Institute of Optics, University of Rochester, Rochester, New York 14627, USA. alonso@optics.rochester.edu
Miguel A
MA
Alonso
Riccardo
R
Borghi
Massimo
M
Santarsiero