Correlation between dielectric and electro-optic properties related to domain dynamics inRbHSeO4crystals

Abstract

The variations of the effective electro-optic coefficient and of the dielectric permittivity as functions of the dc electric field are reported in rubidium hydrogen selenate at room temperature. Their frequency dispersions are measured in the range 20 Hz-1 MHz. The influence of the ac field amplitude on these properties is also studied. It is shown that the dielectric and the electro-optic responses are strongly nonlinear with the amplitude of the ac electric field, and that their frequency dispersions are closely linked to one another, up to the vicinity of the piezoelectric resonances. The role of domain dynamics in the dielectric and electro-optic properties is stressed. The domain contribution to the electro-optic response is explained by means of a simple model based on the tilt of the optical indicatrix in neighboring domains.

Combined effects due to phase, intensity, and contrast in electrooptic modulation: application to ferroelectric materials

“…In particular, the direct intensity modulation induced by the deflection of light will be considered. The properties of phase modulation related to domain dynamics are explained in other publications [2], [3].…”

“…2) can be written as M (1) where is the contrast, M the maximal intensity which could be transmitted if the contrast were equal to unity, 0018-9197/99$10.00 © 1999 IEEE and is the angle between the analyzer and the linear polarization of the output lightwave (2) is the angular position of the analyzer and is the phase shift introduced by the EO crystal. Usually, the maximal intensity M and the contrast are considered constant parameters, and only the phase shift is supposed to be sensitive to the applied electric field (3) where is the length of the crystal, is the wavelength, and is the field-sensitive birefringence of the EO sample…”

“…During the positive half-periods of the field ( ac directly parallel to R ), some domain walls are removed and A B weakens, to the benefit of D . This effect is particularly pronounced in rubidium hydrogen selenate, up to frequencies of several tens of kilohertz, because the ferroelectric domain structure of this crystal is soft enough to be easily reversible by relatively weak ac fields ( 50 V/cm peak-to-peak [2], [3]). In Sénarmont's experiments, the deflection of light leads to different consequences, depending on whether the total transmitted intensity D A B…”

“…Recently, we evidenced a giant EO effect related to domain dynamics in rubidium hydrogen selenate (RHSe) at low frequency [1]- [3] (0-100 kHz). The EO coefficients involved in this effect have been measured with a classical Sénarmont's setup.…”

The Final Stages of Polarization and Monodomain State Stability of the Rochelle Salt Crystals

“…Apart from its own significance, this is important for the investigation of the laws of polarization of ferroics, and for measurements of fundamental characteristics of materials (spontaneous polarization, electric permittivity, dielectric losses, coercive field, piezoelectric, piezooptical and other parameters). Besides high-frequency processes [6], a particular attention is now paid to the slow ones, in which appreciable changes are possible in the defect network of the sample. In particular, for DKDP crystals, a set of relaxation times of polarization (∼ 1 hour) is detected, and the absence of an accurate value of coercive field [1] is stated.…”