Birefringence

Shows a light ray within a birifringent crystal and reflection and transmission at the surface towards air. Answers questions like: * Is the angle of reflection always the same as the angle of incidence? * What happens in case of perpendicular incidence? * Are the wavefronts always perpendicular to the direction of the ray? * How is the polarisation of the rays? * How is the power distributed between ordinary and extraordinary ray? * How does the direction of the optic axis influence all of this?