Topological defects of optical anisotropy parameters caused by the screw dislocations of crystalline structure

We have analyzed spatial distributions of optical birefringence and angle of optical indicatrix rotation caused by inhomogeneous mechanical stresses appearing due to structural screw dislocations in cubic and trigonal crystals. We have shown that accounting for even approximate boundary conditions leads to a physically sound result, zeroing of piezooptically induced birefringence in the vicinity of the dislocation core. Together with the availability of topological defect of the optical indicatrix orientation, this provides the exact conditions for generating singly charged optical vortices.