Low-frequency–dependent electro-optic properties of potassium lithium tantalate niobate single crystals

¹ Department of Physics, Harbin Institute of Technology - Harbin 150001, PRC
² Multifunctional Electronic Materials and Device Research Lab, Department of Electrical and Computer Engineering, The University of Texas at San Antonio - San Antonio, TX 78249, USA

^(a) liyang0202@163.com

Received: 2 March 2013
Accepted: 15 April 2013

Abstract

A series of lead-free ferroelectric potassium lithium tantalate niobate K_0.95Li_0.05Ta_1−xNb_xO₃ (x = 0.78, 0.69, 0.60, 0.52) single crystals were grown using the top-seeded melt growth method. The low-frequency–dependent linear electro-optic properties of K_0.95Li_0.05Ta_1−xNb_xO₃ single crystals in the tetragonal state were investigated using the Senarmont method, autoscanning Mach-Zehnder interferometer technique and AC measurement method at room temperature. The electro-optic measurements were taken with continuous low frequency (from 1 kHz to 100 kHz) of a sinusoidal electric field, and large electro-optic responses were observed. For every component, the values of the electro-optic coefficients γ₃₃, γ₁₃ and γ_c decrease with the increase of frequency. However, the γ₅₁ shows low sensitivity to the change of frequency. γ₃₃, γ₁₃ and γ_c increase with tantalum content, but γ₅₁ decreases with the increase of tantalum content. The electro-optic properties of high-optical-quality K_0.95Li_0.05Ta_1−xNb_xO₃ single crystals forecast their outstanding potential in various electro-optic applications.