, Kenneth J. Chau
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.
electromagnetics, optomechanics, dissipation, left-handed material