Piezo-optic properties of LiNH4SO4 crystals

Abstract

The effect of uniaxial stresses applied along the principle crystallographic directions on the dispersion and temperature dependences of birefringence of LiNH 4 SO 4 crystals is studied. The anomalies of the temperature dependence of birefringence near 220 K have been observed, and their position is shown to depend on the magnitude and direction of crystal uniaxial compression. The spectral and temperature dependences of combined piezo-optic coefficients of these crystals are investigated. It is demonstrated that these coefficients have different signs, are characterized by significant dispersion, and weakly change with temperature; they also have equal absolute values in the vicinity of the isotropic point.

Photoelastic Properties of Trigonal Crystals

“…Comparison of these sums of POC with the analogous ones for principal coefficients π im determined on the direct cut sample makes it possible to confirm the reliability of the POC values as well as piezo-optical identity of the samples cut from the different parts of crystal boule or from different boules. It should be noted that the polarization-optical (see, e.g., [16][17][18][24][25][26][27]) and conoscopic [28][29][30][31][32][33] methods are sometimes used for investigations of crystal photoelasticity. However, in this paper, the photoelasticity of lithium tantalate is solely studied using the interferometric technique.…”

“…It should be noted that the polarization-optical (see, e.g., [16][17][18][24][25][26][27]) and conoscopic [28][29][30][31][32][33] methods are sometimes used for investigations of crystal photoelasticity. However, in this paper, the photoelasticity of lithium tantalate is solely studied using the interferometric technique.…”

THE INFLUENCE OF TEMPERATURE AND UNIAXIAL STRESSES ON THE REFRACTIVE PARAMETERS OF LiNaSO4 CRYSTALS

“…За своїм характером дисперсiйнi змiни п'єзоконстант π 0 12 i π 0 13 кристалу ЛНС доволi схожi на вiдповiднi для кристалу α-LiNH 4 SO 4 [14], однак самi константи сильно рiзняться за значенням: усереднене π 0 12 = 5,6 Бр для α-LiNH 4 SO 4 , тодi як для ЛНС π 0 12 = -2,1 Бр, π 0 13 = -5,8 Бр для α-LiNH 4 SO 4 i π 0 13 = 2,2 Бр для ЛНС.…”

CRYSTAL OPTICAL PARAMETERS OF UNIAXIALLY COMPRESSED LiNaSO4 CRYSTALS

“…2022. Випуск 18 84 відповідних для кристала α-LiNH4SO4[18], однак самі коефіцієнти сильно різняться за значенням: усереднене значення 0 Бр для α-LiNH4SO4, тоді як для ЛНС…”