Non-harmonic potential of a single beam optical trap.

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.

[1]  H. Flyvbjerg,et al.  Power spectrum analysis for optical tweezers , 2004 .

[2]  L. Oddershede,et al.  Optimizing immersion media refractive index improves optical trapping by compensating spherical aberrations. , 2007, Optics letters.

[3]  Norman R. Heckenberg,et al.  Optical tweezers computational toolbox , 2007 .

[4]  Alexander Rohrbach,et al.  Stiffness of optical traps: quantitative agreement between experiment and electromagnetic theory. , 2005, Physical review letters.

[5]  Adriana Fontes,et al.  Electromagnetic forces for an arbitrary optical trapping of a spherical dielectric. , 2006, Optics express.

[6]  C. Schmidt,et al.  Signals and noise in micromechanical measurements. , 1998, Methods in cell biology.

[7]  S. Chu,et al.  Observation of a single-beam gradient force optical trap for dielectric particles. , 1986, Optics letters.

[8]  Christoph F. Schmidt,et al.  Direct observation of kinesin stepping by optical trapping interferometry , 1993, Nature.

[9]  M. Sheetz,et al.  Force of single kinesin molecules measured with optical tweezers. , 1993, Science.

[10]  Jonathon Howard,et al.  Optical trapping of coated microspheres. , 2008, Optics express.

[11]  Ioulia Rouzina,et al.  Quantifying force-dependent and zero-force DNA intercalation by single-molecule stretching , 2007, Nature Methods.

[12]  Fabrice Merenda,et al.  Escape trajectories of single-beam optically trapped micro-particles in a transverse fluid flow. , 2006, Optics express.

[13]  F. Graham Smith,et al.  Optics and Photonics: An Introduction , 2000 .

[14]  Alexandr Jonás,et al.  Three-dimensional tracking of fluorescent nanoparticles with subnanometer precision by use of off-focus imaging. , 2003, Optics letters.

[15]  N. Wax,et al.  Selected Papers on Noise and Stochastic Processes , 1955 .

[16]  O. Axner,et al.  Influence of a glass-water interface on the on-axis trapping of micrometer-sized spherical objects by optical tweezers. , 2003, Applied optics.

[17]  A. Ashkin,et al.  Forces of a single-beam gradient laser trap on a dielectric sphere in the ray optics regime. , 1992, Biophysical journal.

[18]  Shenghua Xu,et al.  Axial deviation of an optically trapped particle in trapping force calibration using the drag force method , 2007 .

[19]  A. Ashkin.  Forces of a single-beam gradient laser trap on a dielectric sphere in the ray optics regime. , 1992, Methods in cell biology.

[20]  Michelle D. Wang,et al.  Force and velocity measured for single molecules of RNA polymerase. , 1998, Science.

[21]  Kirstine Berg-Sørensen,et al.  tweezercalib 2.1: Faster version of MatLab package for precise calibration of optical tweezers , 2006, Comput. Phys. Commun..