Many optical sizing techniques rely on particle/laser interactions. Th
e classical Lorenz-Mie theory describing sphere/plane wave interaction
s is therefore misleading when designing instruments and processing da
ta when the particle size is not small enough with respect to beam dia
meters. In such cases the use of the generalized Lorenz-Mie theory is
required. After summarizing essential features of the generalized Lore
nz-Mie theory for sphere/arbitrary wave interactions, this paper descr
ibes applications of the theory with some emphasis on the analysis of
phase-Doppler anemometers.