POLARISING PRISM Russian patent published in 2012 - IPC G02B5/30 G02B5/04 

FIELD: physics.

SUBSTANCE: prism is composed of three Iceland spar crystals glued together, the optical axes of which are parallel to the input face of the prism and to each other. The refraction index of the glue is less than the refraction index for an ordinary ray. The crystals are cut at an angle which provides total internal reflection of an ordinary ray from the gluing line. The middle crystal is rhomb-shaped in the principal cross-section. The angle between the faces of the crystals, which provides total internal reflection of an ordinary ray, is greater than where n_k is the refraction index of the glue used to glue the crystals; n_o is the refraction index for an ordinary ray in Iceland spar; and less than where n_e is the refraction index of an extraordinary ray in the crystal. Side crystals have a symmetric shape relative the centre of the cross-section of the middle crystal, and the output face is perpendicular to the reflected ordinary ray.

EFFECT: high accuracy of linking the direction of the polarisation plane with the normal to the optical surface of the polariser.

4 cl, 4 dwg