Light tunneling and anomalous reflection from the diffraction of complex annuli: modeling the forward light...

Anomalous reflection and tunneling contributions of the high-frequency forward light scattering by non-absorbing spheres are modeled by the scalar diffraction of two complex annuli-one for TM and TE polarizations. Their complex radii, which depend on the refractive indices and particle size, are derived from the complex angular momentum (CAM) method, thus suggesting possible extensions to non-electromagnetic scattering. Coupled with the diffraction of a disk, and a geometrical optics approximation (GOA) for the refractive contributions, we propose an accurate hybrid model that requires one to two orders of magnitude less computational time than the Lorenz-Mie theory (LMT) in the near field, a crucial improvement for, e.g., inverse methods.