Publication detail

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

Zemanek P, Jonas A, Liska M

Czech title

Popis optických sil působících na částici v Gaussovém poli

English title

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

Type

journal article - other

Language

en

Original abstract

We study the axial force acting on dielectric spherical particles smaller than 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 Gaussian standing wave trap (SWT) and single-beam trap (SBT) as a function of particle size, refractive index, and beam waist size. We show that the SWT produces axial forces at least ten times stronger and permits particle confinement in a wider range of refractive indices and beam waists compared with those of the SBT. (C) 2002 Optical Society of America.

Czech abstract

Příspěvek pojednává o působění opticého pole na částici v Gaussovém poli

English abstract

We study the axial force acting on dielectric spherical particles smaller than 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 Gaussian standing wave trap (SWT) and single-beam trap (SBT) as a function of particle size, refractive index, and beam waist size. We show that the SWT produces axial forces at least ten times stronger and permits particle confinement in a wider range of refractive indices and beam waists compared with those of the SBT. (C) 2002 Optical Society of America.

Keywords in English

FOCUSED LASER-BEAM, RAYLEIGH PARTICLES, TWEEZERS, TRAP, MANIPULATION, MICROSCOPE, FIELDS

RIV year

2003

Released

01.05.2002

ISSN

1084-7529

Journal

Journal of the Optical Society of America A

Volume

19

Number

5

Pages count

10

BIBTEX


@article{BUT40735,
  author="Miroslav {Liška},
  title="Simplified description of optical forces acting on a nanoparticle in the Gaussian standing wave",
  journal="Journal of the Optical Society of America A",
  year="2002",
  volume="19",
  number="5",
  month="May",
  issn="1084-7529"
}