Determination of the Optical Parameters of Uniaxial Optically Active Crystals Taking into Account the Imperfection of Spectrophotometric Complex Elements

The influence of the imperfection of optical elements of a spectrophotometric system on the polarization transmission spectra of a uniaxial optically active absorbing plate has been analyzed by the example of a La3Ta0.25Ga5.25Si0.5O14 crystal, belonging to the langasite family. A comparison of the calculated and experimental transmission spectra for two samples with different thicknesses and optical-axis orientations shows that the optical-activity parameters of a crystal and the angle of deviation of the optical axis from the normal (when this angle is small) can be estimated.