Regular papers

Multi-particle three-dimensional coordinate estimation in real-time optical manipulation

DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, DK-4000 Roskilde, Denmark

^* jesper.gluckstad@fotonik.dtu.dk

Received: 26 June 2009

Abstract

We have previously shown how stereoscopic images can be obtained in our three-dimensional optical micromanipulation system [J. S. Dam et al., Opt. Express 16, 7244 (2008)]. Here, we present an extension and application of this principle to automatically gather the three-dimensional coordinates for all trapped particles with high tracking range and high reliability without requiring user calibration. Through deconvolving of the red, green, and blue colour planes to correct for bleeding between colour planes, we show that we can extend the system to also utilize green illumination, in addition to the blue and red. Applying the green colour as on-axis illumination yields redundant information for enhanced error correction, which is used to verify the gathered data, resulting in reliable coordinates as well as producing visually attractive images.