Fresnoite-type Ba2TiGe2O8 glass-ceramics toward electro-optic device: Crystallization structure and Pockels effect. Issue 15 (December 2020)

• Record Type: Journal Article
• Authors: Okamoto, Haruki; Takahashi, Yoshihiro; Nakamura, Takuma; Terakado, Nobuaki; Miyazaki, Takamichi; Fujiwara, Takumi
• Is Part Of: Journal of the European Ceramic Society. Volume 40:Issue 15(2020)
• Page Start: 5576
• Page End: 5581
• Publication Date: 2020-12
• Subjects: Pockels effect -- Glass-ceramics -- Fresnoite -- Crystallisation -- Nonlinear optical crystal; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2020.06.054
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: 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 Ba2 TiGe2 O8 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 Ba2 TiGe2 O8 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.