COMPUTATION OF THE BEAM-SHAPE COEFFICIENTS IN THE GENERALIZED LORENZ-MIE THEORY BY USING THE TRANSLATIONAL ADDITION THEOREM FOR SPHERICAL VECTOR WAVE-FUNCTIONS

The generalized Lorenz-Mie theory describes the electromagnetic scatte ring of a Gaussian laser beam by a spherical particle. The most intens ive computational aspect of the theory concerns the evaluation of the beam-shape coefficients in the general case of an off-axis location of the scatterer. These beam-shape coefficients can be computed starting from the set of beam-shape coefficients for an on-axis location by us ing the addition theorem for the spherical vector wave functions of th e first kind under a translation of the coordinate origin. (C) 1997 Op tical Society of America.