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David Grier's Home Page

Department of Physics and Center for Soft Matter Research
New York University

Downloadable Software


Particle Tracking Routines


Holographic Optical Trapping Routines


Holographic Video Microscopy Routines

These routines are useful for analyzing holographic video microscopy images of colloidal spheres. They fall into two broad categories. The first uses Rayleigh-Sommerfeld back-propagation to reconstruct the three-dimensional light field scattered by the sample. This is a general, but approximate, approach to hologram analysis. The second fits holographic snapshots to predictions based on the Lorenz-Mie theory of light scattering. This approach can extract extremely precise information from holographic snapshots, but requires an accurate model for light scattering by the object of interest. For colloidal spheres, fits to Lorenz-Mie theory yield each sphere's position in three dimensions, often with nanometer resolution, its radius with nanometer resolution, and its complex refractive index with part-per-thousand precision. See the tutorial to learn how to get started with SPHERETOOL, which is a graphical interactive front end to the entire software suite.


IDLvideo NG

IDLvideo provides IDL with video input capabilities based on open-source software without requiring shared-object libraries. It is based on the MPlayer multimedia player, which it calls through IDL's SPAWN mechanism. This interface has been tested on GNU/Linux and Mac OS X systems, where it can acquire frame-accurate video in real time. It may well work under cygwin. A native Windows port may be more challenging.


Utility Routines

Contact Information

David G. Grier             Department of Physics
                           Center for Soft Matter Research
(212) 998-3713 (voice)     New York University
(212) 995-4016 (FAX)       4 Washington Place
david.grier@nyu.edu        New York, NY 10003

Last Modified: Tue Sep 16 14:27:17 EDT 2014