Servo control of an optical trap.
A versatile optical trap has been constructed to control the position of trapped objects and ultimately to apply specified forces using feedback control. While the design, development, and use of optical traps has been extensive and feedback control has played a critical role in pushing the state of the art, few comprehensive examinations of feedback control of optical traps have been undertaken. Furthermore, as the requirements are pushed to ever smaller distances and forces, the performance of optical traps reaches limits. It is well understood that feedback control can result in both positive and negative effects in controlled systems. We give an analysis of the trapping limits as well as introducing an optical trap with a feedback control scheme that dramatically improves an optical trap's sensitivity at low frequencies.
Center for Biologically Inspired Materials and Material Systems, Duke University, Durham, North Carolina 27708, USA. kurt.wulff@duke.edu
Kurt D
KD
Wulff
Daniel G
DG
Cole
Robert L
RL
Clark
D000465:Algorithms; D001703:Biophysics / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D008846:Micromanipulation; D008853:Microscopy / Q000379:methods; D015233:Models, Statistical; D008962:Models, Theoretical; D052898:Optical Tweezers; D055095:Optics and Photonics; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted