Optical degradation of inductively-coupled plasma lenses by conversion of electromagnetic energy into unsteady flows

This study addresses the onset of convection in an inductively-coupled model plasma lens. The principle of operation of a plasma lens consists of focusing light by tuning the refractive-index distribution, or equivalently, the electron-density field in a partiallyionized gas environment. Departures from axisymmetry in the electron-density distribution are observed in the present three-dimensional calculations, which imply the existence of underlying dynamics of plasma destabilization. Two mechanisms that lead to plasma motion in the lens are studied, namely, gravity-driven thermal convection, and cycleaveraged Lorentz forcing. In turn, it is observed here that the development of motion in the plasma has important implications for the optical performance of the lens.