title: Measurement of optical trapping forces by use of the two-photon-excited fluorescence of microspheres.
abstract: A novel technique for the calibration of laser trapping systems that utilizes two-photon-excited fluorescence of commercial dye-stained microspheres has been demonstrated. The trapping forces as well as the trapping efficiency have been measured for various liquid environments and trapping depths. The trapping efficiency in water was found to decrease with an increase of trapping depths because of the enlargement of the trapping beam waist caused by aberrations of the optical system.
authors.affiliation: The Institute for Lasers, Photonics, and Biophotonics, State University of New York at Buffalo, 458 Natural Sciences Complex, Buffalo, New York 14260-3000, USA.
authors.forename: A V
authors.initials: AV
authors.lastname: Kachynski
authors.forename: A N
authors.initials: AN
authors.lastname: Kuzmin
authors.forename: H E
authors.initials: HE
authors.lastname: Pudavar
authors.forename: D S
authors.initials: DS
authors.lastname: Kaputa
authors.forename: A N
authors.initials: AN
authors.lastname: Cartwright
authors.forename: P N
authors.initials: PN
authors.lastname: Prasad
mesh_terms: D005453:Fluorescence; D008863:Microspheres; D008962:Models, Theoretical; D055095:Optics and Photonics; D017785:Photons