We propose a set of postulates to describe the mechanical interaction between a plane-wave elec- tromagnetic pulse and a dispersive, dissipative slab having a refractive index of arbitrary sign. The postulates include the Abraham electromagnetic momentum density, a generalized Lorentz force law, and a model for absorption in which mass is transferred from the pulse to the medium. These opto-mechanical mechanisms are incorporated into one-dimensional finite-difference time-domain algorithm solving Maxwell's Equations. Calculated values of the instantaneous force densities exerted by the pulse onto the slab, the momentum-per-unit-area of the pulse and slab, and the trajectories of the slab and system center-of-mass are consistent with conservation of global energy, momentum, and center-of-mass velocity at all times, regardless of the presence of dispersion and dissipation, or of the sign of the real part of the refractive index of the slab material.
Citation: Optics Express
Pub Type: Journals
electromagnetics, optomechanics, dissipation, left-handed material