1 January 1998 Miniaturized optical microprobe for sizing in multiple-scattering systems
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Instruments based on photon counting in the visible part of the spectrum with subsequent signal autocorrelation of the light intensity fluctuation are widely used for the characterization of clear media, but are performance limited if multiple scattering samples or particle suspensions with an inherent diffusion limitation are probed. These systems are classified as turbid media. We give advanced approaches as to how multiple scattering systems predominantly existing in industry can be examined, in order to resolve the sizes of suspended scattering centers. Latex particles and emulsions were used as models. Monte Carlo calculations of the light transport mechanisms in turbid media were performed and compared with measurements. A dynamic light scattering instrument was used to perform measurements on highly concentrated and turbid samples. For example, with particle standards of 83 nm, a size of 85 nm +/- 5.8 nm (n equals 10) was obtained and particles with a size of 895 nm were measured to be 895 nm +/- 9.1 nm (n equals 10). The influence of multiple scattering on the autocorrelation function was both measured and calculated. We have shown that our calculations are in good agreement with the test results obtained and it was found that our miniaturized instrument is a valuable tool to measure particle sizes in turbid media.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Karsten Dierks, Karsten Dierks, Matthias Dieckmann, Matthias Dieckmann, J. Krueger, J. Krueger, "Miniaturized optical microprobe for sizing in multiple-scattering systems", Proc. SPIE 3199, Biomedical Systems and Technologies II, (1 January 1998); doi: 10.1117/12.301114; https://doi.org/10.1117/12.301114

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