Abstract
<jats:p>The main refractive indices of natural inorganic uniaxial crystal CaCO3 are determined using an Abbe refractometer equipped with a polarizing filter for the visible range. A source of white light equipped with seven colored filters was used for this purpose. The linear birefringence of calcite was computed as the difference between the main refractive indices. In order to obtain more information about the dependence of calcite linear birefringence on light wavelength, the channeled spectra method was used. Computed linear birefringence for channeled spectra is a continuous function of the light wavelength. Based on the birefringence values, some compensatory layers working for different purposes were computed for the yellow radiation of a sodium lamp.</jats:p>