Three-dimensional forward scattering particle image velocimetry applied to a microscopic field-of-view

We have completed a model to predict the three-dimensional position of a spherical particle from the image formed by a high numerical aperture microscope. Although this information may be exploited in a number of different ways, we are particularly interested in determining the three components of velocity for seed particles following a flow. The basis of the model is to use Mie theory to determine the complete electromagnetic field scattered by a spherical particle and then to propagate the scattered field across the interface between sample and air and then through a high aperture microscope and ultimately to a detector.