Ab initio study of the radiation pressure on dielectric and magnetic media

Abstract

The Maxwell stress tensor and the distributed Lorentz force are applied to calculate forces on lossless media and are shown to be in excellent agreement. From the Maxwell stress tensor, we derive analytical formulae for the forces on both a half-space and a slab under plane wave incidence. It is shown that a normally incident plane wave pushes the slab in the wave propagation direction, while it pulls the half-space toward the incoming wave. Zero tangential force is derived at a boundary between two lossless media, regardless of incident angle. The distributed Lorentz force is applied to the slab in a direct way, while the half-space is dealt with by introducing a finite conductivity. In this regard, we show that the ohmic losses have to be properly accounted for, otherwise differing results are obtained. This contribution, together with a generalization of the formulation to magnetic materials, establishes the method on solid theoretical grounds. Agreement between the two methods is also demonstrated for the case of a 2-D circular dielectric particle.

Colloquium: Gripped by light: Optical binding

“…In addition to spherical objects, spheroidal or cylindrical ones are also often considered theoretically ͑Nieminen et al, Grzegorczyk et al, 2006c;Nieminen, Kröner, et al, 2007;Xu et al, 2007͒. Optical forces acting on particles with more complex shapes must be calculated using numerical schemes; for example, the coupled dipole method ͑CDM͒ ͑Hoekstra . If the object is much larger than the trapping light wavelength, the ray-optics model can be used ͑Ashkin, 1992; Gussgard et al, 1992;Gu et al, 1997;Mazolli et al, 2003͒. The second approach derives the optical force from the Lorentz force acting on both currents J due to the polarization of dielectric and bound charges e at the boundaries ͑Mansuripur, , 2005Kemp et al, 2005, ͗F͘ = 1 2 Re ͭ͵ ͗ e E * + J ϫ B * ͘dV ͮ .…”

The distribution of electromagnetic waves and forces in a dispersive chiral cylinder

“…The relation between the electric polarization vectors P e , P c , induced electric currents J, J c , and electric field E, as well as the relation between the magnetic polarization vectors M n , M c , induced magnetic currents K, K c , and magnetic field H can be defined as [12] …”

“…In recent years, optical forces [1,2,3,4,5,6,7,8,9,10,11,12] in different structures and devices have been a subject of great interest because of theirs application in optical tweezers [2,3,4], tractor beams [5], etc. Most of these studies have been focused on the structures composed of passive materials [3,4], whereas forces on active media have received little attention.…”

“…For the analysis of electromagnetic waves and optical forces on effective electric or magnetic dispersive particles [12], not dielectric or metal particles, the Lorentz force formula incorporated with the FDTD method for conventional nonchiral particles has been reported [11]. The wave propagation and Lorentz force density in one dimensional chiral slab is discussed [17].…”

Enhancement of Electromagnetic Force by Localized Fields in One-Dimensional Photonic Crystal

“…Each layer may experience both normal and tangential forces. If one layer is made of lossless media, the tangential force is zero [10], regardless of incidence angle. Otherwise, if it is lossy, the tangential force is not zero [5].…”