Abstract

Optical single-particle counters based on scattered intensity measurements have response functions that oscillate with particle size, and the magnitudes of the oscillations limit measurement resolution. To estimate attainable resolution, the intensity scattered into a circular aperture viewing the crossing of two laser beams was calculated using the generalized Mie scattering solution for refractive indices of 1.33, 1.592, 1.7, 2.0, 2.5, and 3.0 (without an imaginary component). The particle size range considered was 0.3-6.2 μm in 0.1-μm steps for receiving lenses with f/Nos. 1, 2, and 4.

© 1987 Optical Society of America