Spherical distributed dielectric resonators

Spherical radially periodic dielectric structures inhibit electromagnetic propagation over a complete solid angle and a finite frequency range. The range of inhibited frequencies is linear in the amplitude of the radial modulation. Depending on the phase, the amplitude, and the inner boundary of the dielectric modulation, localized photon modes may occur within the gap. The internal field distributions and scattering characteristics of spherical dielectric resonators are analyzed numerically.