Optically driven nanorotors: experiments and model calculations.
We show that asymmetric nanorods rotate under the laser radiation pressure, irrespective of the polarization of the light, when trapped in laser tweezers. If a nanorod is not quite transparent to the trapping laser radiation, the radiation pressure force generates a non zero torque on the asymmetric nanorods making them rotate at a moderate speed. Our experimental observations on radiation pressure driven rotations of MgO and Si nanorods in optical trap show that the efficiency of the rotors depends directly on their transmittance at the trapping wavelength. We propose theoretical models to estimate the rotational speed at different laser powers for a rotor with shape asymmetries or surface irregularities.
Khan
Manas
M
Department of Physics, Indian Institute of Science, Bangalore 560012, India.
Sood
A K
AK
Deepak
F Leonard
FL
Rao
C N R
CN
D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D004735:Energy Transfer; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D012399:Rotation; D013499:Surface Properties; D014159:Transducers
D046911:Macromolecular Substances