CALCULATION OF SCATTERED-LIGHT INTENSITY CAUSED BY A PARTICLE ARBITRARY POSITIONED IN A LASERBEAM BY USING 2-DIMENSIONAL FOURIER-TRANSFORM

Detailed scattered light calculations are necessary for the design of phase-Doppler anemometers. The Mie theory used very often in laser ane mometry is based on the assumption of a homogeneous field around a lig ht scattering particle. There isn't any location in the laserbeam wher e this assumption is fulfiled. The autors present a new method (Fourie r-Lorenz-Mie theory FLMT) for the calculation of flight scattering of spherical particles in an inhomogeneous field. By using the two dimens ional Fourier transform light scattering in an inhomogenous field can be reduced to the Mie theory. The capability of the new FLMT method is shown in comparison to Lorenz-Mie theory, Generalized Lorenz-Mie Ther oy (GLMT) and Coupled Dipole method.