force calibration For many applications exact knowledge of the optical forces acting on the confined particles is important. Therefore different methods for force calibration of optical tweezers have been developed, which will be presented and discussed on this page. Three dimensional force calibration of optical tweezers W. Singer, S. Bernet, N. Hacker and M. Ritsch-Marte Journal of Modern Optics, 75, 14, 2000 Department of Medical Physics, University of Innsbruck, Austria Abstract: We demonstrate a method for 3-dimensional force calibration of optical tweezers by recording the trapping dynamics of polystyrene beads. This is realized by time-resolved detection of the horizontal and vertical position of a bead which is drawn to the focus of a laser beam. The method provides real time characterization of the force pro® le of an optical trap in all directions. PDF - full document