Sizing of submicrometer particles using a phase–Doppler system

Based on an analysis of the response of a phase-Doppler system to a Rayleigh scatterer, the basic requirements for the application of this technique in the Rayleigh and near-Rayleigh range are established. Using Mie-scattering theory, we computed the response curves of the corresponding phase-Doppler systems for various materials. The possibilities for particle sizing as well as particle material recognition in the submicrometer range are highlighted. Measurements with submicrometer latex spheres in water demonstrate the feasibility of the application of the phase-Doppler technique in the near-Rayleigh range.