  Placing graphene on uniaxial substrates may have interesting application
potential for graphene-based photonic and optoelectronic devices. Here we
analytically derive the dispersion relation for graphene plasmons on uniaxial
substrates and discuss their momentum, propagation length and polarization as a
function of frequency, propagation direction and both ordinary and
extraordinary dielectric permittivities of the substrate. We find that the
plasmons exhibit an anisotropic propagation, yielding radially asymmetric field
patterns when a point emitter launches plasmons in the graphene layer.
