Radiation Pressure and Photon Momentum in Negative-Index Media

Radiation pressure and photon momentum in negative-index media are no different than their counterparts in ordinary (positive-index) materials. This is because the parameters responsible for these properties are the admittance, sqrt(epsilon/mu), and the group refractive index n_g of the material (both positive entities), and not the phase refractive index, n=sqrt(epsilon*mu), which is negative in negative-index media. One approach to investigating the exchange of momentum between electromagnetic waves and material media is via the Doppler shift phenomenon. In this paper we use the Doppler shift to arrive at an expression for the radiation pressure on a mirror submerged in a negative-index medium. In preparation for the analysis, we investigate the phenomenon of Doppler shift in various settings, and show the conditions under which a so-called "inverse" Doppler shift could occur. We also argue that a recent observation of the inverse Doppler shift upon reflection from a negative-index medium cannot be correct, because it violates the conservation laws.Comment: 14 pages, 8 figures, 17 equations, 5 reference

Theoretical analysis of the force on the end face of a nano-filament exerted by an outgoing light pulse

The slight deformations observed upon transmission of a light pulse through a short length of a silica glass nano-filament offer the possibility of determining the momentum of light inside the filament. Using precise numerical calculations that take into account not only the electromagnetic momentum inside and outside the filament, but also the Lorentz force exerted by a light pulse in its entire path through the nano-waveguide, we conclude that the net effect of a short pulse exiting the nano-filament should be a pull force on the end face of the filament.Comment: 11 pages, 7 figures, 13 equations, 7 reference

Equivalence of total force (and torque) for two formulations of the Lorentz law

Two formulations of the Lorentz law of force in classical electrodynamics yield identical results for the total force (and total torque) of radiation on a solid object. The object may be surrounded by the free space or immersed in a transparent dielectric medium such as a liquid. We discuss the relation between these two formulations and extend the proof of their equivalence to the case of solid objects immersed in a transparent medium.Comment: 5 pages, 2 figures, 15 equations, 6 reference