Characteristics of extinction for a hexagonal crystal

The formulae for cross-sections and extinction efficiency factors are derived for the cases when a polarized optical radiation interacts with a hexagonal plate and a hexagonal column. A hexagonal crystal has a pair of parallel faces. For such a crystal, there always are the refraction beams, leaving the crystal in the direction of incident wave propagation. As a rule, cross-sections of these beams are commensurable with the geometrical shadow of a crystal. Hence, the diffraction and scattered field are comparable to each other. Each of these fields is determined by means of one and the same formalism. Therefore, the diffraction and scattered fields have the identical structure, that permits to sum them taking into account a mutual phase shift. Using the methods of physical optics as a formalism makes it possible to obtain the analytical expressions for characteristics of extinction for a hexagonal plate and for a hexagonal column as well.