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We investigated the Pockels effect in polycrystalline materials consisting of highly oriented polar fresnoite-type Sr2TiSi2O8 fabricated using perfectly surface-crystallized glass-ceramics (PSCGCs). The chemical composition of the precursor glass was shown to significantly affect the crystallized texture, e.g., the crystal orientation and appearance of amorphous nanoparasites in the domains, resulting in variations in the Pockels constants. Single crystals exhibiting spontaneous polarization possessed large structural anisotropy, leading to a strong dependence of the nonlinearoptical properties on the direction of polarized light. This study suggests that variations in the Pockels constants (r13 and r33) and tuning of the r13/r33 ratio can be realized in PSC-GC materials. [ABSTRACT FROM AUTHOR]

We have fabricated perfectly-surface-crystallized glass-ceramics (PSC-GCs) consisting of polar frenoite-type Sr 2 TiSi 2 O 8 by different crystallization-process conditions, i.e., isothermal treatment at 880 °C for 72 h and 960 °C for 1 h, and have examined their Pockels effect in this study. The PSC-GCs obtained by the lower-temperature process exhibited the Pockels coefficients, i.e., r 13 ∼ 3.0 pm/V and r 33 ∼ 2.4 pm/V, and the coefficients exceeded the reported values of the PSC-GCs with Sr 2 TiSi 2 O 8 phase. The improvement of Pockels effect is attributed to the higher crystal-orientation, which is provided by the lower-temperature condition. [ABSTRACT FROM AUTHOR]

Silicate glass has been used for long time because of its advantages from material's viewpoint. In this paper, we report the observation of Pockels effect by Mach-Zehnder interferometer in polycrystalline ceramics made from a ternary silicate glass via crystallization due to heat-treatment, i.e., glass-ceramics. Since the silicate system is employed as the precursor, merits of glass material are fully utilized to fabricate the optical device component, in addition to that of functional crystalline material, leading us to provide an electro-optic device, which is introducible into glass-fiber network. [ABSTRACT FROM AUTHOR]

Optical modulation based on second-order optical nonlinearity is required to control a light-wave for telecommunication with optical-fiber network, and its controlling device is basically constructed using a single crystal material. To fabricate an optical device material having the connectivity to glass fiber, glass-ceramic (GC) processing is effective. In this study, a bulk-like GC material with a polar fresnoite-type Ba 2 TiGe 2 O 8 were successfully fabricated. The obtained GCs were formed by densely-aggregated structure of two phase, fresnoite-type (major phase) and tetragermanate (minor phase). The fresnoite-type Ba 2 TiGe 2 O 8 domains with submillimeter-sized were oriented with the polar c -axis perpendicular to sample plane. The GC sample exhibited the optical modulation driven by Pockels effect, and the Pockels coefficients could be quantitatively estimated, i.e., r 13 = 2.3 ± 0.1 pm/V and r 33 = 2.5 ± 0.1 pm/V. The experimental results demonstrate the potential of higher Pockels coefficients by microscopic structural studies, because of good controllability of the polar orientation and suppression of secondary phase. [ABSTRACT FROM AUTHOR]