Interference enhancement of the internal fields at structural scattering resonances of a coated sphere

Appl Opt. 1990 Jul 20;29(21):3180-7. doi: 10.1364/AO.29.003180.

Abstract

We examine the interior electromagnetic energy density of a coated nonabsorbing sphere at a number of scattering resonances. As is the case for an uncoated sphere, the interior energy density becomes large at the a(p)(l) and b(p)(l) resonances. It becomes especially large for p - 1 values of the coating thickness at resonance. These p - 1 enhancements are analogous to the interference maxima that occur in the intensity reflectance of two thin films in contact.