Stiffer optical tweezers through real-time feedback control

Wallin, A.E., Ojala, H., Haeggstrom, E. and Tuma, R. (2008) Stiffer optical tweezers through real-time feedback control. Applied Physics Letters, 92 (22). Art. No. 224104. ISSN 0003-6951

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Abstract

Using real-time re-programmable signal processing we connect acousto-optic steering and back-focal-plane interferometric position detection in optical tweezers to create a fast feedback controlled instrument. When trapping 3 µm latex beads in water we find that proportional-gain position-clamping increases the effective lateral trap stiffness ~13-fold. A theoretical power spectrum for bead fluctuations during position-clamped trapping is derived and agrees with the experimental data. The loop delay, ~19 µs in our experiment, limits the maximum achievable effective trap stiffness.

Item Type:	Article
Copyright, Publisher and Additional Information:	© 2008 American Institute of Physics. This is an author produced version of a paper published in Applied Physics Letters. Uploaded in accordance with the publisher's self-archiving policy.
Academic Units:	The University of Leeds > Faculty of Biological Sciences (Leeds) > Institute of Molecular and Cellular Biology (Leeds) The University of Leeds > University of Leeds Research Centres and Institutes > Astbury Centre for Structural Molecular Biology (Leeds)
Depositing User:	Sherpa Assistant
Date Deposited:	10 Jul 2008 15:01
Last Modified:	08 Feb 2013 17:05
Published Version:	http://dx.doi.org/10.1063/1.2940339
Status:	Published
Publisher:	American Institute of Physics
Refereed:	Yes
Identification Number:	10.1063/1.2940339
Related URLs:	Author
URI:	http://eprints.whiterose.ac.uk/id/eprint/4064

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