Near-field impulse response examination of backscattering from dielectric spheres

Abstract

The backscattered component of the normalized Poynting vector impulse response is evaluated at selected times on a plane normal to the direction of pulse propagation and in the near field of a dielectric sphere. The computations for spheres with refractive indices of 1.60 + 0.01i and 2.25 + 0.01i are consistent with the physical interpretations of the high frequency analogs of axial, stationary, and glory rays and internal surface waves. Flux maxima associated with glory and stationary rays appear first on the axis normal to the plane of polarization and change to the axis of polarization as their analogs change polarity. Latter stages of the glory ray appear to propagate in a mode similar to internal surface waves.