OPTICAL PROPERTIES IN CRYSTALS 



165 



Fig. 1 — Position of electric, magnetic and normal vectors for an electromagnetic plane 



wave in a crystal. 



Fig. 2 — Rotated axes and angles for relating them to unrotated axes. 



liy choosing the original x, y, z axes so that /3i2 = /3i3 = 1S23 = and using 

 the values jSn = |5i , ^ti = ^1 , 1833 = 1S3 this gives the equation 



2 2 2 



2 I 2 l~ 2 



V ^ a ^ 



0. 



(21) 



For transmission along the X axis «i = \,rh = fh = and the two velocities 

 are given by 



^,2 = ^2^2 = b\ v' = /33F2 = c\ (22) 



