Online measurement of nanoparticle size distribution in flowing Brownian motion system using laser diode self-mixing interferometry

low cost and few additional optical elements required, is promising to be applied to the online measurement of the particle size distribution in a flowing Brownian motion system. 

In this paper, the online measurement is realized by the laser diode self-mixing interferometry 

with a quick signal processing technique and a quick inversion algorithm. The total power spectrum of the self-mixing signal is achieved, and the impact of particle motions on the total power spectrum is researched. A method is proposed for retrieving the particle size distribution, which is validated 

by experimental tests.