title: Non-harmonic potential of a single beam optical trap.
abstract: Since the invention of optical traps based on a single laser beam, the potential experienced by a trapped specimen has been assumed harmonic, in the central part of the trap. It has remained unknown to what extent the harmonic region persists and what occurs beyond. By employing a new method, we have forced the trapped object to extreme positions, significantly further than previously achieved in a single laser beam, and thus experimentally explore an extended trapping potential. The potential stiffens considerably as the bead moves to extreme positions and therein is not well described by simple Uhlenbeck theories.
authors.affiliation: The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen, Denmark.
authors.forename: A C
authors.initials: AC
authors.lastname: Richardson
authors.forename: S N S
authors.initials: SN
authors.lastname: Reihani
authors.forename: L B
authors.initials: LB
authors.lastname: Oddershede
mesh_terms: D000465:Algorithms; D002138:Calibration; D004581:Electronics / Q000379:methods; D004867:Equipment Design; D007834:Lasers; D008846:Micromanipulation / Q000379:methods; D008853:Microscopy / Q000379:methods; D016011:Normal Distribution; D052898:Optical Tweezers; D055095:Optics and Photonics; D010825:Physics / Q000379:methods; D014159:Transducers