Radiation forces on spheres in loosely focused Gaussian beam: ray-optics regime

Analytic expressions for radiation force on a sphere in a loosely focused Gaussian beam are derived in suitable form for applications by the photon stream method in the ray-optics regime. For perfect reflecting spheres, an analytic solution for the scattering force and a simplified expression for the gradient force are obtained. The computation results presented are consistent with those of previous theoretical studies and reported experimental results. (c) 2006 Optical Society of America.