Abstract

Homodyne light fluctuation spectroscopy is combined with an electrophoresis apparatus to provide a technique that rapidly measures electrophoretic mobilities of charged particles suspended in a liquid medium. Two parallel laser beams, polarized in the same direction, are focused into a scattering cell by a cylindrical lens. The laser beams interfere at the focal point of the lens to produce a fringe intensity profile. As scattering particles are driven through the fringes, the scattered light intensity is modulated. This modulation is detected by digital autocorrelation of photoelectron pulses from a photomultiplier. With this technique the electrophoretic mobility of 1-μ diam monodisperse polystyrene spheres was determined to be 4.6 ± 0.2 (μ/sec)/(V/cm) in water.

© 1975 Optical Society of America

Diffraction analysis of Doppler signal characteristics for a cross-beam laser Doppler velocimeter

D. M. Robinson and W. P. Chu
Appl. Opt. 14(9) 2177-2183 (1975)

Role of multiple scattering in cross-correlated light scattering with a single laser beam

James A. Lock
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Spectral Analysis and Cross-Correlation Techniques for Photon Counting Measurements on Fluid Flows

T. S. Durrani and C. A. Greated
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SNR in optical velocimeters: effect of particle number density

J. H. C. Chan and E. A. Ballik
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Laser Cross-Beam Intensity-Correlation Spectrum for a Turbulent Flow

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