Scattering phase function measurements on single particles and on particle ensembles

We present measurements of the light-scattering phase function of selected carbon and ash particles in the geometric-optics regime in which the particle diameter is much larger than the wavelength of the light source. Measurements were performed on both single particles and particle ensembles. This was accomplished with two separate methodologies: an electrodynamic levitator for single-particle measurements and a particle feeder for the ensemble measurements. For such methodology, two irradiation sources were utilized: an argon-ion laser (lambda = 496 nm) and a xenon lamp. Results of the normalized phase functions are presented. (C) 2004 Optical Society of America.