  Expressions corresponding to the transmission of a uniaxial optically active
crystal platelet are provided for an optical axis parallel and perpendicular to
the plane of interface. The optical activity is taken into account by a
consistent multipolar expansion of the crystal medium response due to the path
of an electromagnetic wave. Numerical examples of the effect of the optical
activity are given for quartz platelets of chosen thicknesses. The optical
activity's effects on the variations of the transmission of quartz platelets as
a function of the angle of incidence is also investigated.
