Resonant scattering from inhomogeneous nonspherical targets

Abstract

A method is proposed for solving problems in which either scalar or vector waves impinge at an arbitrary angle on an inhomogeneous nonspherical target whose size is comparable to the wavelength of the incident radiation. This method reduces a partial differential equation, the Helmholtz wave equation, to an ordinary differential equation through selection of angular trial functions composed of weighted sums of spherical harmonics. The wave equation then becomes a coupled set of radial differential equations which are discretized and solved by matrix methods, enforcing boundary conditions on the surface of the smallest sphere which completely encloses the target. The method is an extension of partial wave expansion and reduces to it exactly when the target is spherically symmetric.