SCATTERING OF A DIAGONALLY INCIDENT FOCUSED GAUSSIAN-BEAM BY AN INFINITELY LONG HOMOGENEOUS CIRCULAR-CYLINDER

I expand the radiation potential of an arbitrary monochromatic electro magnetic wave in the cylindrical coordinate eigenfunctions of the scal ar Helmholtz equation. Since the resulting beam shape coefficients are found to be an inverse Fourier transform of the z component of the be am fields, the incident Gaussian beam is parameterized by a Fourier an gular spectrum of plane waves. The beam's partial-wave coefficients ar e then obtained, as well as the scattered fields produced by the inter action of the beam with an infinitely long homogeneous circular cylind er. The fields are evaluated analytically in the far zone by the metho d of stationary phase, and the physical interpretation of the results are discussed extensively. (C) 1997 Optical Society of America.