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

A series of lead-free ferroelectric potassium lithium tantalate niobate K 0.95 Li 0.05 Ta 1− x Nb x O 3 ( 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 0.95 Li 0.05 Ta 1− x Nb x O 3 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 γ 33 , γ 13 and γ c decrease with the increase of frequency. However, the γ 51 shows low sensitivity to the change of frequency. γ 33 , γ 13 and γ c increase with tantalum content, but γ 51 decreases with the increase of tantalum content. The electro-optic properties of high-optical-quality K 0.95 Li 0.05 Ta 1− x Nb x O 3 single crystals forecast their outstanding potential in various electro-optic applications.