Wave propagation in rotating magnetised plasmas

Abstract

Wave propagation properties in a medium are fundamentally affected when this medium is moving instead of at rest. In isotropic dielectric media rotation has two noteworthy contributions: one is a mechanically induced circular birefringence, which materialises as a rotation of the polarisation, the other is image rotation, which corresponds to a rotation of the transverse structure of a wave. Here, we review the effect of rotation in a magnetised plasma. We also point out applications to both astrophysical phenomena and laboratory devices. We first show that the mechanical effect of rotation on polarisation is in a magnetised plasma superimposed onto the classical Faraday rotation and that failing to account for this new contribution could lead to errors in the interpretation of polarimetry data. We also demonstrate that image rotation is recovered in plasmas for a number of low-frequency magnetised plasma waves carrying orbital angular momentum and that this phenomenon holds promise for the development of new rotation diagnostic tools in plasmas.