Athermal phase directions in barium borate crystals

Филиппов В.В. Атермальные фазовые направления в кристаллах бората бария // Оптический журнал. 2010. Т. 77. № 5. С. 66–68.

Filippov V.V. Athermal phase directions in barium borate crystals [in Russian] // Opticheskii Zhurnal. 2010. V. 77. № 5. P. 66–68.

V. V. Filippov, "Athermal phase directions in barium borate crystals," Journal of Optical Technology. 77(5), 348-349 (2010). https://doi.org/10.1364/JOT.77.000348

Circular cones of propagation directions of ordinary or extraordinary waves exist in BaB2O4 crystals for which the phase of the wave remains constant when the crystal is heated. The axis of the cones is parallel to the optic axis of the crystal, while the cone half-angle at a wavelength of 532.1nm equals 77°16′ for the ordinary wave and 64°42′ for the extraordinary wave.