Abstract

The presence of an interface or structure can significantly impact the characteristic behavior of a radiating system. Specifically, frequency and lifetime shifts induced by the structure are interpretable within the context of creating a “photonic bandgap,” i.e., an energy band for which wave propagation is isotropically forbidden. Utilizing a classical model, we directly treat the interaction of a radiating dipole within a spherical Bragg structure. The real and imaginary portions of the reflected field, evaluated at the source position, determine the lifetime variations and frequency shifts, respectively.¹ Employing a Green’s function method, we derive and numerically solve coupled-amplitude equations within the Bragg region. This method is part of a rigorous 3-D vector formulation used in determining the reflected field strength. We examine radiative lifetime variations and resonance frequency shifts for idealizations of the structure and source. We also show that the spherical structure is capable of inhibiting radiation from a central, finite-sized region. These calculations are of fundamental interest for understanding dipole-surface interactions, particularly in 3-D spherical geometries requiring a vector formulation; the development is also of potential practical interest as applied to spherical cavity and photonic structure design.

© 1993 Optical Society of America