arXiv 1202.16002012-02physics.opticscond-mat.soft

Imaging Multiple Colloidal Particles by Fitting Electromagnetic Scattering Solutions to Digital Holograms

Jerome Fung, Rebecca W. Perry, Thomas G. Dimiduk, Vinothan N. Manoharan

备注：: 20 pages, 6 figures, 1 table
发表信息：: Journal of Quantitative Spectroscopy and Radiative Transfer, 113 (18), 2482-2489 (2012)
DOI：: 10.1016/j.jqsrt.2012.06.007

英文摘要：

Digital holographic microscopy is a fast three-dimensional (3D) imaging tool with many applications in soft matter physics. Recent studies have shown that electromagnetic scattering solutions can be fit to digital holograms to obtain the 3D positions of isolated colloidal spheres with nanometer precision and millisecond temporal resolution. Here we describe the results of new techniques that extend the range of systems that can be studied with fitting. We show that an exact multisphere superposition scattering solution can be used to fit holograms of colloidal clusters containing up to six spheres. We also introduce an approximate and computationally simpler solution, Mie superposition, that is valid for multiple spheres spaced several wavelengths or more from one another. We show that this method can be used to fit holograms of several spheres on an emulsion droplet, and we give a quantitative criterion for assessing its validity.

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