Two-photon quantum dot excitation during optical trapping.
A single CW infrared laser beam can simultaneously trap and excite an individual colloidal quantum dot. Though the laser light is relatively weak, the excitation occurs through two-photon absorption. This finding eliminates the demand for an excitation light source in addition to a trapping laser in nanoscale experiments with simultaneous force-manipulation and quantum dot visualization. Also, we demonstrate that optical trapping efficiencies of individual quantum dots do not correlate with their emission wavelength or physical size.
Jauffred
Liselotte
L
The Niels Bohr Institute, University of Copenhagen, Denmark.
Oddershede
Lene B
LB
D008027:Light; D052898:Optical Tweezers; D017785:Photons; D045663:Quantum Dots; D012542:Scattering, Radiation