Optical alignment and confinement of an ellipsoidal nanorod in optical tweezers: a theoretical study

0384141 - ÚPT 2013 RIV US eng J - Journal Article
Trojek, Jan - Chvátal, Lukáš - Zemánek, Pavel
Optical alignment and confinement of an ellipsoidal nanorod in optical tweezers: a theoretical study.
Journal of the Optical Society of America A. Roč. 29, č. 7 (2012), s. 1224-1236. ISSN 1084-7529. E-ISSN 1520-8532
R&D Projects: GA ČR GA202/09/0348; GA MŠMT ED0017/01/01
Institutional support: RVO:68081731
Keywords : ellipsoidal nanorod * optical tweezers * Rayleigh approximation
Subject RIV: BH - Optics, Masers, Lasers
Impact factor: 1.665, year: 2012

Within the Rayleigh approximation, we investigate the behavior of an individual ellipsoidal metal nanorod that is optically confined in three dimensions using a single focused laser beam. We focus on the description of the optical torque and optical force acting upon the nanorod placed into a linearly polarized Gaussian beam (scalar description of the electric field) or a strongly focused beam (vector field description). The study comprises the influence of the trapping laser wavelength, the angular aperture of focusing optics, the orientation of the ellipsoidal nanorod, and the aspect ratio of its principal axes. The results reveal a significantly different behavior of the nanorod if the trapping wavelength is longer or shorter than the wavelength corresponding to the longitudinal plasmon resonance mode. Published experimental observations are compared with our theoretical predictions with satisfactory results.
Permanent Link: http://hdl.handle.net/11104/0213875