A detailed review of the fundamentals of propagation of plane waves in
dielectric, homogenous and anisotropic mediums, and of the properties of
optically anisotropic materials is presented. A mathematical expression for the
refractive indices is made for uniaxial and biaxial crystals, but attention is
particularly focused on the uniaxial case. Huygens' construction of the double
refraction using the geometrical method of the index surfaces has been studied
and applied to uniaxial crystals of calcite and quartz when the optic axis is
parallel to the plane of incidence. The incidence walk–off angle for any arbitrary
uniaxial crystal orientation has been derived and temperature–dependent
dispersion curves at normal incidence for quartz and calcite crystals are
obtained for a wavelength range of 350–750 nm.
