Momentum of light (Conference Presentation)

Abstract

There are many ways to calculate the optical forces acting on scattering particles such as Maxwell's stress tensor, Lorentz forces, gradient and scattering forces, Lorenz-Mie formalism, T-matrix. All these approaches use the electromagnetic field and define the amount of linear momentum transferred to the scattering particles. The resulting momentum transferred is proportional to the intensity of the incident fields, however, the momentum of single photons (hbar k) does not naturally appear in these classical expressions. Here, we discuss an alternative Maxwell's stress tensor based formalism that renders the classical electromagnetic field momentum compatible to the quantum mechanical one. This is achieved through the introduction of the quantum conversion which allows the transformation, including units, of the classical fields to wave-function equivalent fields.