Dichroism is observed in CdS, CdS:Cu, CdS:Mn, CdS:In, and CdS:O single crystals. The activated crystals contain 0.1% of activator except in the case of oxygen activator which is ∼1%. Inversion of the crystal sign, i.e., positive to negative, is observed in CdS crystals at 5245 A. In the case of activated crystals, the inversion point was obtained by extrapolation and found to coincide with that
... [Show full abstract] of the “pure” CdS crystal. A simplified method for measuring indexes of refraction over a wide range has also beed devised.