Premium
A Double Gaussian Beam Method for the Determination of Particle Size, Direction and Velocity
Author(s) -
Castagner Jean Luc,
Jones Alan R.
Publication year - 2004
Publication title -
particle and particle systems characterization
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.877
H-Index - 56
eISSN - 1521-4117
pISSN - 0934-0866
DOI - 10.1002/ppsc.200400892
Subject(s) - optics , gaussian beam , physics , beam (structure) , birefringence , amplitude , gaussian , prism , particle (ecology) , scattering , beam diameter , laser , m squared , intensity (physics) , laser beams , oceanography , quantum mechanics , geology
This paper describes a technique aimed at measuring particle size by light scattering from gaussian laser beams. The uncertainties in illumination due to the beam shape are avoided by determination of the direction and velocity. The method, which we arbitrarily called the Two Beam System (TBS), uses a simple birefringent prism to separate the incident laser beam into two orthogonally polarised overlapping parallel beams. The relative delay and amplitudes of the intensities scattered out of the orthogonal polarisations are indicative of the particle direction and velocity. Having obtained the direction of travel of the particle, its size is then obtained from the scattered intensity using Mie theory.