Tracking and characterizing particles with holographic video microscopy

摘要

In-line holography to create images of a specimen, such as one or more particles dispersed in a transparent medium. Analyzing these images with results from light scattering theory yields the particles' sizes with nanometer resolution, their refractive indexes to within one part in a thousand, and their three dimensional positions with nanometer resolution. This procedure can rapidly and directly characterize mechanical, optical and chemical properties of the specimen and its medium.

主权项

1. A method for characterizing a specimen, comprising:
providing a holographic microscope; providing a collimated laser beam to the holographic microscope; scattering the collimated laser beam off the specimen to generate a scattered portion; generating an on-axis hologram including an interference pattern from an unscattered portion of the collimated laser beam and the scattered portion; recording the interference pattern for subsequent analysis wherein the step of recording the interference pattern includes a step of normalizing the interference pattern by dividing the interference pattern by a background form of interference pattern wherein the background form is selected from the group of a previously recorded background image form, a normalization constant form and a numerical model for a background illumination pattern form, and the normalized interference pattern is selectively fitted to a particular prediction methodology of light scattering, thereby providing characteristic information about the specimen; and using the characteristic information for measuring at least one of a spatial location, a mechanical property, an optical property and a chemical property of the specimen.