<title>Polarized-type phase Doppler method for simultaneous measurements of particle velocity, diameter, and refractive index</title>

Abstract

A new polarized-type phase Doppler method is proposed for simultaneous measurements of particle size, velocity and refractive index on the basis of the phases of two polarized Doppler beat signals in a single scattering direction. Light scattered by a moving particle is divided into two rays, which are then detected with different polarization angles to transmit dominantly reflected or refracted rays. Signal phases of these two rays are measured with respect to the phase of beat signal obtained from the reference detector in the scattering plane. The particle diameter can be obtained from the phase of the reflected ray, whereas the particle refractive index can be determined from the phase ratio of the reflected and refracted rays. We carried out numerical simulations and experiments to confirm the usefulness of the prosed method.