Measurement of Particle Diameter Based on In-line Digital Holography

A digital in-line holographic recording and reconstruction method was used in the particle image for the diameter measurement. The main advantage of in-line holography is that the setup is very simple and the reconstruction process is not complicated. In digital holography, image reconstruction is carried out numerically on a computer by using the observed hologram patterns and some quantitative information derived from the reconstructed images which were properly segmented by using threshold selection method (MEM). On the base, the particle boundary was determined by Laplacian of Gauss operator. The diameter of particles could be obtained by calculating the size of the particle. In numerical simulations, one particle and particles in a space were individually discussed. The experiments indicate the relative error is less than 10%.