On the off-centre angle and the refractive index difference due to the birefringence of F_A(II) centres in KCl:Li crystals

Abstract

Based on the dichroism of the FA (II) KCl:Li centres the off-centre angle of the Li+ ion was measured to be 13.5+or-1 degrees at 26 K. Furthermore, the birefringence of the centres was verified and the difference between the refractive indexes relating to the two preferred directions was directly derived from the absorption spectra measured with polarized wave.

Fibre Optic Information Reading from KCl: Li FA-Centre Optical Memory

“…It is also worth to mention that the polarized ruby laser light induces temporary anisotropy of the crystal. Because of the induced birefringence [7] the polarization vector of the incident off axis polarized probe light rotates while propagating through the crystal. In Fig.…”