SIZE DEPENDENCE OF NONLINEAR MIE SCATTERING IN MICRODROPLETS ILLUMINATED BY ULTRASHORT PULSES

We present results of experiments to determine the spectral and angula r dependence of nonlinear scattering by water microdroplets of radii r anging from 1 to 32 mu m illuminated by ultrashort laser pulses. The m ain process observed is third-harmonic generation (THG). Moreover, in contrast with linear Mie scattering, the angular pattern of the THG is remarkably stable over the size range 8-32 mu m. (C) 1998 Optical Soc iety of America.