@inproceedings{8416b78cd9194ba2b2698b144b0e6a5f,
title = "Real-time control of optical tweezers",
abstract = "Optically trapped microshperes can be manipulated by steering the trap beam, while the object position is measured with sub-nanometer resolution. A fast steering system is required to create feedback loop for measurements at a constant force or to increase position detection precision by trap stiffening. Using a real-time re-programmable digital signal processor, we combine steering and position detection to create a fast and versatile closed-loop feedback controlled instrument. We describe the construction and calibration of the instrument. We show that a proportional gain position-clamp algorithm can achieve about 10-fold increase in effective trap stiffness while higher gains lead to unwanted resonances.",
author = "Wallin, {Anders E.} and Heikki Ojala and Anders Korsb{\"a}ck and Edward Haeggstr{\"o}m and Roman Tuma",
year = "2007",
month = sep,
doi = "10.1117/12.737269",
language = "English",
series = "Proceedings of SPIE",
publisher = "International Society for Optics and Photonics SPIE",
booktitle = "Optical Trapping and Optical Micromanipulation IV",
address = "United States",
}