  Rotational Fresnel drag - or orbital Faraday rotation - in a rotating
magnetised plasma is uncovered and studied analytically for Trivelpiece-Gould
and Whistler-Helicon waves carrying orbital angular momentum (OAM). Plasma
rotation is shown to introduce a non-zero phase shift between OAM-carrying
eigenmodes with opposite helicities, similarly to the phase-shift between spin
angular momentum eigenmodes associated with the classical Faraday effect in a
magnetised plasma at rest. By examining the dispersion relation for these two
low-frequency modes in a Brillouin rotating plasma, this Faraday-Fresnel
rotation effect is traced back to the combined effects of Doppler shift,
centrifugal forces and Coriolis forces. In addition, rotation is further shown
to lead to rotation- and azimuthal mode-dependent longitudinal group velocity,
therefore predicting the Faraday-Fresnel splitting of the enveloppe of a wave
packet containing a superposition of OAM-carrying eigenmodes with opposite
helicities.
