Orientation of optical axes in absorptive crystals with arbitrary permittivity tensors

The direct relation has been established between the orientations of the op tical axes and the components of the inverse complex permittivity tensor of an absorptive crystal possessing an arbitrary symmetry. The particular for ms of the general relationships for triclinic crystals, characterized by an arbitrary degree of absorption, are obtained for crystals of all the other symmetry systems. The relationships obtained acquire a substantially simpl ified form for weakly absorptive crystals. The consideration is based on th e relationship established for the components of the inverse permittivity t ensor in the Cartesian coordinates and the diadic form of this tensor, whic h is related to the directions of the optical axes. (C) 2000 MAIK "Nauka/In terperiodica".