Real-time particle tracking at 10,000 fps using optical fiber illumination

TY - JOUR

T1 - Real-time particle tracking at 10,000 fps using optical fiber illumination

AU - Otto, Oliver

AU - Czerwinski, Fabian

AU - Gornall, Joanne L.

AU - Stober, Gunter

AU - Oddershede, Lene Broeng

AU - Seidel, Ralf

AU - Keyser, Ulrich F.

PY - 2010/10/25

Y1 - 2010/10/25

N2 - We introduce optical fiber illumination for real-time tracking of optically trapped micrometer-sized particles with microsecond time resolution. Our light source is a high-radiance mercury arc lamp and a 600μm optical fiber for short-distance illumination of the sample cell. Particle tracking is carried out with a software implemented cross-correlation algorithm following image acquisition from a CMOS camera. Our image data reveals that fiber illumination results in a signal-to-noise ratio usually one order of magnitude higher compared to standard Köhler illumination. We demonstrate position determination of a single optically trapped colloid with up to 10,000 frames per second over hours. We calibrate our optical tweezers and compare the results with quadrant photo diode measurements. Finally, we determine the positional accuracy of our setup to 2 nm by calculating the Allan variance. Our results show that neither illumination nor software algorithms limit the speed of real-time particle tracking with CMOS technology.

AB - We introduce optical fiber illumination for real-time tracking of optically trapped micrometer-sized particles with microsecond time resolution. Our light source is a high-radiance mercury arc lamp and a 600μm optical fiber for short-distance illumination of the sample cell. Particle tracking is carried out with a software implemented cross-correlation algorithm following image acquisition from a CMOS camera. Our image data reveals that fiber illumination results in a signal-to-noise ratio usually one order of magnitude higher compared to standard Köhler illumination. We demonstrate position determination of a single optically trapped colloid with up to 10,000 frames per second over hours. We calibrate our optical tweezers and compare the results with quadrant photo diode measurements. Finally, we determine the positional accuracy of our setup to 2 nm by calculating the Allan variance. Our results show that neither illumination nor software algorithms limit the speed of real-time particle tracking with CMOS technology.

U2 - 10.1364/OE.18.022722

DO - 10.1364/OE.18.022722

M3 - Journal article

SN - 1094-4087

VL - 18

SP - 22722

EP - 22733

JO - Optics Express

JF - Optics Express

IS - 22

ER -