Explicit computation of gradient and nongradient contributions to optical forces in the discrete-dipole approximation

Vance Wong, Mark A Ratner

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

We present an efficient, discrete-dipole-approximation-based method for computing gradient and nongradient contributions to the optically induced force on neutral, polarizable particles in a field. We compare numerical data from this method with those generated using previously devised computational approaches for computing total forces. The agreement is generally adequate, and rounding error is the likely cause for differences among results obtained from the three methods. For both one- and two-sphere targets, nongradient forces generally make a nonnegligible contribution. For spheres, the gradient force often nearly cancels a component of the nongradient force, so that the radiation-pressure component is approximately equal to the net force. These results are contrary to the commonly assumed dominance of the gradient force for nanometer-sized particles.

Original languageEnglish
Pages (from-to)1801-1814
Number of pages14
JournalJournal of the Optical Society of America B: Optical Physics
Volume23
Issue number9
DOIs
Publication statusPublished - 2006

Fingerprint

dipoles
gradients
approximation
neutral particles
radiation pressure
causes

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

Cite this

@article{f41d8b2933c94f33b2ed86562db6c69e,
title = "Explicit computation of gradient and nongradient contributions to optical forces in the discrete-dipole approximation",
abstract = "We present an efficient, discrete-dipole-approximation-based method for computing gradient and nongradient contributions to the optically induced force on neutral, polarizable particles in a field. We compare numerical data from this method with those generated using previously devised computational approaches for computing total forces. The agreement is generally adequate, and rounding error is the likely cause for differences among results obtained from the three methods. For both one- and two-sphere targets, nongradient forces generally make a nonnegligible contribution. For spheres, the gradient force often nearly cancels a component of the nongradient force, so that the radiation-pressure component is approximately equal to the net force. These results are contrary to the commonly assumed dominance of the gradient force for nanometer-sized particles.",
author = "Vance Wong and Ratner, {Mark A}",
year = "2006",
doi = "10.1364/JOSAB.23.001801",
language = "English",
volume = "23",
pages = "1801--1814",
journal = "Journal of the Optical Society of America B: Optical Physics",
issn = "0740-3224",
publisher = "The Optical Society",
number = "9",

}

TY - JOUR

T1 - Explicit computation of gradient and nongradient contributions to optical forces in the discrete-dipole approximation

AU - Wong, Vance

AU - Ratner, Mark A

PY - 2006

Y1 - 2006

N2 - We present an efficient, discrete-dipole-approximation-based method for computing gradient and nongradient contributions to the optically induced force on neutral, polarizable particles in a field. We compare numerical data from this method with those generated using previously devised computational approaches for computing total forces. The agreement is generally adequate, and rounding error is the likely cause for differences among results obtained from the three methods. For both one- and two-sphere targets, nongradient forces generally make a nonnegligible contribution. For spheres, the gradient force often nearly cancels a component of the nongradient force, so that the radiation-pressure component is approximately equal to the net force. These results are contrary to the commonly assumed dominance of the gradient force for nanometer-sized particles.

AB - We present an efficient, discrete-dipole-approximation-based method for computing gradient and nongradient contributions to the optically induced force on neutral, polarizable particles in a field. We compare numerical data from this method with those generated using previously devised computational approaches for computing total forces. The agreement is generally adequate, and rounding error is the likely cause for differences among results obtained from the three methods. For both one- and two-sphere targets, nongradient forces generally make a nonnegligible contribution. For spheres, the gradient force often nearly cancels a component of the nongradient force, so that the radiation-pressure component is approximately equal to the net force. These results are contrary to the commonly assumed dominance of the gradient force for nanometer-sized particles.

UR - http://www.scopus.com/inward/record.url?scp=33749614874&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749614874&partnerID=8YFLogxK

U2 - 10.1364/JOSAB.23.001801

DO - 10.1364/JOSAB.23.001801

M3 - Article

AN - SCOPUS:33749614874

VL - 23

SP - 1801

EP - 1814

JO - Journal of the Optical Society of America B: Optical Physics

JF - Journal of the Optical Society of America B: Optical Physics

SN - 0740-3224

IS - 9

ER -