As of 1 April 2026, the PSJD database will become an archive and will no longer accept new data. Current publications from Polish scientific journals are available through the Library of Science: https://bibliotekanauki.pl
The temperature-spectral dependencies of refractive indices and birefringence in wide temperature (77-1000 K) and spectral (250-850 nm) regions in LiKSO_{4} crystals were measured. The isotropic point of LiKSO_{4} crystals was investigated. It was shown that annealing and X-ray irradiation display insignificantly the isotropic point to a visible region of spectrum.