Ultra-high resolution particle size measurement based on scattering spectrum analysis—simulation and experiment

Abstract

This paper focuses on the properties of light scattering spectra from a spherical particle and their application for particle size measurement. The influence of particle size and scattering angle on the scattering spectra are investigated and simulated. An ultra-resolution particle dimension measurement method was proposed based on detecting the peak of scattering spectra. An accurate spectral peak location strategy based on the spectral shape features is adopted to reduce the spectra peak positioning error caused by dispersion. The size of smaller particle is measured by locating a wide scattering spectral peak at a larger scattering angle to achieve higher measurement sensitivity, while the size of larger particle is measured by locating a narrow scattering spectral peak at a smaller angle to achieve a larger measurement range. If the spectral resolution of the spectrometer is 0.8 nm, the particle size resolution of 1.1 nm and 8.3 nm are achieved for measured particles with sizes ranging from 0.25µm to 1µm and measured particles with sizes ranging from 1µm to 10µm, respectively. And if the spectrometer with picometer resolution is used, the particle size resolution is expected to be on the order of picometers.