Simplified description of optical forces acting on a nanoparticle in the Gaussian standing wave

0205469 - UPT-D 20020019 RIV US eng J - Journal Article
Zemánek, Pavel - Jonáš, Alexandr - Liška, M.
Simplified description of optical forces acting on a nanoparticle in the Gaussian standing wave.
Optical Society of America. Journal A: Optics, Image Science, and Vision. Roč. 19, č. 5 (2002), s. 1025 - 1034. ISSN 0740-3232
R&D Projects: GA ČR GA101/98/P106; GA ČR GA202/99/0959; GA ČR GA101/00/0974
Institutional research plan: CEZ:AV0Z2065902
Keywords : Gaussian tanding wave
Subject RIV: BH - Optics, Masers, Lasers
Impact factor: 1.688, year: 2002

We study the axial force acting on dielectric spherical particles smallerthan the trapping wavelength that are placed in the Gaussian standing wave. We derive analytical formulas for immersed particles with relative refractive indices close to unity and compare them with the numerical results obtained by generalized Lorenz-Mie theory (GLMT). We show that the axial optical force depends periodically on the particle size and that the equilibrium position of the particle alternates between the standing-wave antinodes and nodes. For certain particle sizes, gradient forces from the neighboring antinodes cancel each other and disable particle confinement. Using the GLMT we compare maximum axial trapping forces provided by the Gaussianstanding wave trap (SWT) and single-beam trap (SBT) as a function of particle size, refractive index, and beam waist size.
Permanent Link: http://hdl.handle.net/11104/0101082