Method for complete determination of a refractive-index tensor by bireflectance: application to CdWO_4

The bireflectance effect is observed when a light beam is internally reflected in an anisotropic material. Generally, an unpolarized light beam splits into four beams on reflection. A new method for simultaneous measurement of the three refractive indices, based on laser-beam splitting due to bireflectance, is demonstrated in the biaxial CdWO4 crystal. The three principal refractive indices of CdWO4 were obtained in the visible range. At Lambda = 633 nm, nX = 2.09 +/- 0.01, nY - nX = 0.052 +/- 0.001, and nZ -nX = 0.114 +/- 0.002.