Temperature dependence of the quadratic electrooptic effect and estimation of antipolarization of ADP

Abstract

Measurements of the temperature dependence of the quadratic electrooptic coefficient |g 1111 -g 2211 | of ADP were made. The coefficient is found to decrease with an increase in temperature. The results show that the intrinsic quadratic electrooptic coefficient |M 1111 -M 2211 | defined in terms of polarization also dependes on temperature. Employing the temperature dependence of |M 1111 -M 2211 | estimation of antipolarization in lowtemperature antiferroelectric phase of ADP is made.

FTIR, XRD, SEM, TGA Investigations of Ammonium Dihydrogen Phosphate (ADP) Single Crystal

“…They are still widely used as nonlinear optical devices and the choicest electro -optic materials having wide practical application [2][3][4][5][6][7][8][9][10][11][12][13] . Several researchers have carried out a lot of studies on pure ADP crystals [14][15][16] .…”

Estimation of spontaneous antipolarization of ADP based on magnitude of fourth‐order electrooptic effect

“…For example, in perovskites the assumption allows to relate the quadratic electrooptic effect in the cubic paraelectric phase and linear electrooptic coefficients [9,10] or spontaneous birefringence [11] with the spontaneous polarization in the low-temperature ferroelectric phase. Despite the fact that the assumption is only an approximation, it should be noted that, contrary to the coefficients defined in terms of electric field, their changes with temperature are weak [5,12].…”

“…Traditional experimental methods applicable in ferroelectrics for measurements of their spontaneous polarization cannot be employed to determine the spontaneous antipolarization of antiferroelectrics. Thus, the electrooptic effect in ADP is of special interest as related through the spontaneous birefringence to the spontaneous antipolarization [3][4][5].…”

Temperature dependence of linear electrooptic coefficients r 113 and r 333 in lithium niobate

“…The experimental approach adopted in this work involved the dynamic polarimetric method described previously [4,5]. The value of r eff was evaluated from the modulation index of the emerging light intensity detected by a photodiode by means of a lock-in technique.…”

“…In each cycle, the subsequent temperature points were approached approximately linearly in 2-3 hours, then the temperature was stabilised for an additional one hour before measurements at specific temperatures. The optical system used in these measurements was biased to the middle of its transmission characteristic by taking advantage of the temperature dependence of the natural birefringence of the measured crystal [4,5]. The investigations were made in air on the samples with dimensions of 30´30´4 mm 3 .…”