title: Tunable optical tweezers for wavelength-dependent measurements.
abstract: Optical trapping forces depend on the difference between the trap wavelength and the extinction resonances of trapped particles. This leads to a wavelength-dependent trapping force, which should allow for the optimization of optical tweezers systems, simply by choosing the best trapping wavelength for a given application. Here we present an optical tweezer system with wavelength tunability, for the study of resonance effects. With this system, the optical trap stiffness is measured for single trapped particles that exhibit either single or multiple extinction resonances. We include discussions of wavelength-dependent effects, such as changes in temperature, and how to measure them.
authors.affiliation: Physics and Astronomy Department, Appalachian State University, 525 Rivers Street, Boone, North Carolina 28608, USA. hesterbc@appstate.edu
authors.forename: Brooke
authors.initials: B
authors.lastname: Hester
authors.forename: Gretchen K
authors.initials: GK
authors.lastname: Campbell
authors.forename: Carlos
authors.initials: C
authors.lastname: López-Mariscal
authors.forename: Carly Levin
authors.initials: CL
authors.lastname: Filgueira
authors.forename: Ryan
authors.initials: R
authors.lastname: Huschka
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Halas
authors.forename: Kristian
authors.initials: K
authors.lastname: Helmerson
mesh_terms: D002138:Calibration; D052898:Optical Tweezers; D013696:Temperature; D014783:Viscosity