MEASUREMENT OF BEAM-SHAPE COEFFICIENTS IN THE GENERALIZED LORENZ-MIE THEORY FOR THE ON-AXIS CASE

The use of the generalized Lorenz-Mie theory that describes the intera ction between a spherical particle and an arbitrarily shaped beam requ ires knowledge of the beam-shape coefficients (BSC's) that describe th e illuminating beam. Classically, these BSC's are evaluated from an a priori mathematical description of the illuminating beam. We propose a method that relies on intensity measurements along the beam axis that permits one to measure directly the BSC's of an actual beam in the la boratory. (C) 1998 Optical Society of America.