n Strong
(angle-dependent) absorption for
photons with energy comparable or lower than the plasma frequency.
n Strong absorption around the e- and ion cyclotron frequency.
n Below the plasma freq, one of the two
modes may be non-propagating: a whistler. Whistlers
have very large, divergent refractive index (Melrose, 1986).
n Appearance of cut-off
energies and evanescent modes which can
not propagate into the medium.
n If the refractive index has large
imaginary part : highly damped modes.
They can not penetrate much
below the surface (Jackson, 1975).