Image Information Obtained Using a Charge-Coupled Device (CCD) Camera During an Immersion Liquid Evaporation Process for Measuring the Refractive Index of Solid Particles

Abstract

The refractive index is a fundamental physical property of a medium, which can be used for the identification and purity issues of all media. Here we describe a refractive index measurement technique to determine simultaneously the refractive index of different solid particles by monitoring the transmittance of light from a suspension using a charge-coupled device (CCD) camera. An important feature of the measurement is the liquid evaporation process for the refractive index matching of the solid particle and the immersion liquid; this was realized by using a pair of volatile and non-volatile immersion liquids. In this study, refractive indices of calcium fluoride (CaF) and barium fluoride (BaF) were determined using the proposed method.

Determination of the Refractive Index of Particles Through the Immersion Solid Matching Method

“…The RI of a particle can be determined by an experimental method based on RI matching between the immersion fluid and the particles. This well-known traditional immersion liquid method has been successfully utilized in microscopy [5], spectroscopy [6], and machine vision [7] to determine the RI of particles. In the literature, different variations of the liquid immersion method are described to assess the RI of particles.…”