Electromagnetic waves in uniaxial crystals: General formalism with an   application to Bessel beams
  We present a mathematical formalism describing the propagation of a completely general electromagnetic wave in a birefringent medium. Analytic formulas for the refraction and reflection from a plane interface are obtained. As a particular example, a Bessel beam impinging at an arbitrary angle is analyzed in detail. Some numerical results showing the formation and destruction of optical vortices are presented. 
S. Hacyan, R. Jauregui