title: Three-dimensional force measurements in optical tweezers formed with high-NA micromirrors.
abstract: The three-dimensional trap stiffness of optical tweezers formed with high-NA micromirrors is investigated by back-focal-plane interferometry and power spectrum analysis. Normalized stiffness values of kappaxy/Ptrap=1.2(microN/m)/mW and kappaz/Ptrap=0.52(microN/m)/mW in the transverse and axial directions, respectively, have been measured for polystyrene spheres with a radius of 1.03 microm. Compared with high-NA microscope objectives, micromirrors achieve much better trapping performances, particularly in the axial direction.
authors.affiliation: Advanced Photonics Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland. fabrice.merenda@a3.epfl.ch
authors.forename: Fabrice
authors.initials: F
authors.lastname: Merenda
authors.forename: Mathieu
authors.initials: M
authors.lastname: Grossenbacher
authors.forename: Sylvia
authors.initials: S
authors.lastname: Jeney
authors.forename: László
authors.initials: L
authors.lastname: Forró
authors.forename: René-Paul
authors.initials: RP
authors.lastname: Salathé