电极图案及其连接设计对KTP晶体周期极化的调控研究

doi:10.15541/jim20250383

无机材料学报 ›› 2026, Vol. 41 ›› Issue (8): 1125-1132.DOI: 10.15541/jim20250383 CSTR: 32189.14.jim20250383

电极图案及其连接设计对KTP晶体周期极化的调控研究

谭婷婷¹(), 宋旭东²^,³^,⁴, 赵炜迪²^,³^,⁴, 覃祺¹, 何小玲²^,³^,⁴(), 张昌龙¹^,²^,³^,⁴()

¹ 桂林电子科技大学材料科学与工程学院, 桂林 541000
² 桂林百锐光电技术有限公司, 桂林 541000
³ 广西超硬材料重点实验室, 桂林 541000
⁴ 中国有色桂林矿产地质研究院有限公司, 桂林 541000

收稿日期:2025-09-29 修回日期:2025-10-23 出版日期:2026-08-20 网络出版日期:2025-11-11
通讯作者: 张昌龙, 教授. E-mail: 573370768@qq.com;
何小玲, 教授. E-mail: hxlpl@hotmail.com
作者简介:谭婷婷(2000-), 女, 硕士研究生. E-mail: 1441232713@qq.com
基金资助:
广西科技计划项目(2023AB10008);广西科技计划项目(2023AB01273);中国有色矿业集团科技计划项目(2023KJZX007)

Regulation of Periodic Poling in KTP Crystals via Electrode Pattern and Connection Design

TAN Tingting¹(), SONG Xudong²^,³^,⁴, ZHAO Weidi²^,³^,⁴, QIN Qi¹, HE Xiaoling²^,³^,⁴(), ZHANG Changlong¹^,²^,³^,⁴()

¹ School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin 541000, China
² Guilin Bairay Photoelectric Technology Co., Ltd., Guilin 541000, China
³ Guangxi Key Laboratory of Superhard Materials, Guilin 541000, China
⁴ China Nonferrous Metal (Guilin) Geology and Mining Co., Ltd., Guilin 541000, China

Received:2025-09-29 Revised:2025-10-23 Published:2026-08-20 Online:2025-11-11
Contact: ZHANG Changlong, professor. E-mail: 573370768@qq.com;
HE Xiaoling, professor. E-mail: hxlpl@hotmail.com
About author:TAN Tingting (2000-), female, Master candidate. E-mail: 1441232713@qq.com
Supported by:
Science and Technology Program of Guangxi Province(2023AB10008);Science and Technology Program of Guangxi Province(2023AB01273);Science Technology Project of China Nonferrous Metal Mining Group(2023KJZX007)

摘要/Abstract

摘要：

基于磷酸钛氧钾(KTiOPO₄, KTP)晶体铁电畴结构设计获得的周期极化KTP (PPKTP)晶体, 由于其产生的纠缠光子源具有低功耗、小体积、高纠缠品质等优越性能, 逐渐成为量子光学中产生纠缠量子光源的核心元器件。在用电场极化法制备PPKTP晶体时, 非均匀电场会导致不规则的畴结构, 进而对非线性光学性能产生不利影响, 因此电场的均匀性是极化过程的核心控制要素。为提升PPKTP晶体极化过程中电场的均匀性, 本研究通过优化电极图案与电极连接结构, 系统开展了仿真与实验验证。基于有限元分析, 对不同电极图案结构的空间电场分布进行了模拟, 提出了一种双边圆角电极图案以减轻边缘电场集中, 以及用来优化电场分布均匀性的并联多触点电极连接方式。采用金相显微镜对极化晶体的畴结构进行了表征, 通过对晶体铁电畴形貌进行实验验证发现双边圆角结构的电极图案能够有效减轻尖端效应, 而并联式多触点电极连接方式能够明显提升电场的均匀性, 从而为获得高质量的反转畴提供了关键条件。最终, 实验得到了畴壁平直, 周期为46 μm, 占空比约为(50±1)%的水热法PPKTP晶体。本工作为PPKTP制备过程中的电场均匀化设计提供了一种简便、高效且结构合理的设计方案。

关键词: 磷酸钛氧钾, 周期极化磷酸钛氧钾, 有限元分析, 电场分布

Abstract:

Periodically poled potassium titanyl phosphate (PPKTP) crystals, engineered based on the ferroelectric domain structure of KTiOPO₄ (KTP), have emerged as a core component for generating entangled quantum light sources in quantum optics. This is attributed to the entangled photon sources they produce, which exhibit superior performance such as low power consumption, compact size, and high entanglement quality. During the preparation of PPKTP crystals via the electric field poling method, inhomogeneous electric fields can lead to irregular domain structures, adversely affecting their nonlinear optical properties. Therefore, electric field uniformity is a critical control factor in the poling process. To improve the electric field homogeneity during the polarization of PPKTP crystals, this study systematically optimized both the electrode pattern and the electrode connection structure through simulation and experimental validation. Using finite element analysis, the spatial electric field distributions of different electrode patterns were simulated. A double-sided rounded electrode pattern was proposed to mitigate edge electric field concentration, while a parallel multi-contact electrode connection method was introduced to further enhance the uniformity of the electric field distribution. The domain structures of the poled crystals were characterized using metallographic microscopy. Experimental results from the ferroelectric domain morphology analysis confirmed that the double-sided rounded electrode pattern effectively alleviates the tip effect, and the parallel multi-contact connection method significantly improves electric field uniformity, thereby providing key conditions for high-quality domain inversion. Ultimately, hydrothermally grown PPKTP crystals were obtained with straight domain walls, a period of 46 μm, and a duty cycle of approximately (50±1)%. This work offers a simple, efficient, and structurally rational design solution for achieving uniform electric field distribution in the preparation of PPKTP crystals.

Key words: KTiOPO₄, PPKTP, finite element analysis, electric field spatial distribution

中图分类号:

TQ174

谭婷婷, 宋旭东, 赵炜迪, 覃祺, 何小玲, 张昌龙. 电极图案及其连接设计对KTP晶体周期极化的调控研究[J]. 无机材料学报, 2026, 41(8): 1125-1132.

TAN Tingting, SONG Xudong, ZHAO Weidi, QIN Qi, HE Xiaoling, ZHANG Changlong. Regulation of Periodic Poling in KTP Crystals via Electrode Pattern and Connection Design[J]. Journal of Inorganic Materials, 2026, 41(8): 1125-1132.

图/表 12

表1 仿真建模所用到的主要参数

Table 1 Key parameters used in simulation modeling

Parameter	Numerical value
Polarization period	46 μm
Electrode width	12 μm
Crystal thickness	1 mm
Electrode thickness	0.3 μm
Relative dielectric constant of potassium titanium phosphate	13
Voltage connection end radius	130 μm
Polarization voltage	3 kV

图1 不同电极图案结构

Fig. 1 Different electrode patterns (a) Rectangular electrode; (b) Rectangular electrode with rounded corners on one side; (c) Rectangular electrode with rounded corners on both sides

图2 不同电极图案的空间电场分布

Fig. 2 Spatial electric field distributions for different electrode patterns (a) Frame-shaped electrode; (b) Single-sided rounded-corner electrode; (c) Double-sided rounded-corner electrode. Colorful figures are available on website

图3 不同电极图案的边缘电场分布

Fig. 3 Edge electric field distributions for different electrode patterns (a) Frame-shaped electrode; (b) Single-sided rounded-corner electrode; (c) Double-sided rounded-corner electrode

图4 极化后的样品图

Fig. 4 Images of the polarized samples (a) Cracked crystal after polarization of the frame-shaped electrode; (b) Crystal domain morphology after polarization of a single-sided rounded-corner electrode; (c) Crystal domain morphology after polarization of a double-sided rounded-corner wide electrode

图5 不同电极连接方式示意图

Fig. 5 Schematic diagrams of different electrode connection methods (a) Bilateral wiring electrode connection method; (b) Parallel multi- contact electrode connection schematic

图6 不同电极连接结构的空间电场分布

Fig. 6 Spatial electric field distribution diagrams for different electrode connection configurations (a-c) Overall simulation: (a) bilateral connection structure, (b) parallel 4-contact connection structure, (c) parallel 8-contact connection structure; (d-f) Surface simulation: (d) bilateral connection structure, (e) parallel 4-contact connection structure, (f) parallel 8-contact connection structure. Colorful figures are available on website

图7 不同电极连接结构所选内切面的空间电场分布

Fig. 7 Spatial electric field distributions on selected internal cross-sections for different electrode connection structures (a) Bilateral electrode connection method; (b) Parallel 4-contact electrode connection method; (c) Parallel 8-contact electrode connection method. Colorful figures are available on website

图8 不同电极连接结构下晶体外侧x-z面的内部空间电场分布

Fig. 8 Internal spatial electric field distributions on the outer x-z plane of the crystal exterior under different electrode connection configurations (a) Bilateral wiring electrode connection method; (b) Parallel 4-contact electrode connection method; (c) Parallel 8-contact electrode connection method. Colorful figures are available on website

图9 晶体表面所选直线上的电场强度分布

Fig. 9 Electric field distribution maps along the selected line on the crystal surfaces (a) Overall distribution and (b) local magnification of the selected region for the bilateral wiring electrode connection method; (c) Overall distribution and (d) local magnification of the selected region for the parallel 4-contact electrode configuration; (e) Overall distribution and (f) local magnification of the selected region for the parallel 8-contact electrode configuration

图10 不同电极连接方式下极化后KTP晶体+z面的畴壁形貌

Fig. 10 Domain wall morphologies of polarized KTP crystals along the +z plane under different electrode connection configurations (a-c) ×100 magnification: (a) bilateral wiring electrode connection method, (b) parallel 4-contact electrode connection method, (c) parallel 8-contact electrode connection method; (d-f) ×200 magnification: (d) bilateral wiring electrode connection method, (e) parallel 4-contact electrode connection method, (f) parallel 8-contact electrode connection method

图11 不同电极连接方式下其特征直线上的反转畴宽度

Fig. 11 Widths of the reversed domains on the characteristic straight line under different electrode connection methods (a) Bilateral wiring electrode connection mode; (b) Parallel 4-contact electrode connection mode; (c) Parallel 8-contact electrode connection mode

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电极图案及其连接设计对KTP晶体周期极化的调控研究

Regulation of Periodic Poling in KTP Crystals via Electrode Pattern and Connection Design

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