Ukrainian Journal of Physical Optics 

V.Kardash, G.Romanyuk, R.Brezvin, V.Kurlyak and V.Stadnyk

The influence of uniaxial mechanical stresses, applied along the principal crystal-physical axes, on the principal values of birefringence ?ni is studied for TGS crystals with 5% L-threonine admixture. It is revealed that ?ni are quite sensitive to the mechanical stresses. The baric coefficients dT_c/ds_m for the phase transition temperature appear to be less than those for the pure TGS. Temperature dependences and dispersion of the piezooptic coefficients are calculated. The jump-like changes in all of the piezooptic coefficients occurring at the Curie temperature in the doped crystals are explained with the contrib-utions of a secondary electrooptic effect.

Key words: birefringence, uniaxial pressure, phase transitions, piezooptic coefficients
PACS: 77.84.Jd, 42.81.Gs,78.20.Hp

doi 10.3116/16091833/4/4/173/2003

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