Su Yawen, Zhang Xinyu, Chen Haiwei, Li Shifeng, Ma Jianan, Li Wei, Niu Yunfei, Qin Qi, Yang Shaoguang, Deng Yu, Zhang Yong, Hu Xiaopeng, Zhu Shining
National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, School of Physics, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
College of Integrated Circuit Science and Engineering, National and Local Joint Engineering Laboratory of RF Integration and Micro-Assembly Technology, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
Nanophotonics. 2024 May 29;13(18):3477-3484. doi: 10.1515/nanoph-2024-0168. eCollection 2024 Aug.
Photonic devices based on ferroelectric domain engineering in thin film lithium niobate are key components for both classical and quantum information processing. Periodic poling of ridge waveguide can avoid the selective etching effect of lithium niobate, however, the fabrication of high-quality ferroelectric domain is still a challenge. In this work, we optimized the applied electric field distribution, and rectangular inverted domain structure was obtained in the ridge waveguide which is beneficial for efficient nonlinear frequency conversions. Second harmonic confocal microscope, piezoresponse force microscopy, and chemical selective etching were used to characterize the inverted domain in the ridge waveguide. In addition, the performance of nonlinear frequency conversion of the periodically poled nano-waveguide was investigated through second harmonic generation, and the normalized conversion efficiency was measured to be 1,720 % W cm, which is close to 60 % that of the theoretical value. The fabrication technique described in this work will pave the way for the development of high-efficiency, low-loss lithium niobate nonlinear photonic devices.
基于薄膜铌酸锂中铁电畴工程的光子器件是经典和量子信息处理的关键组件。脊形波导的周期性极化可以避免铌酸锂的选择性蚀刻效应，然而，高质量铁电畴的制造仍然是一个挑战。在这项工作中，我们优化了施加电场分布，并在脊形波导中获得了矩形反转畴结构，这有利于高效的非线性频率转换。利用二次谐波共聚焦显微镜、压电力显微镜和化学选择性蚀刻对脊形波导中的反转畴进行了表征。此外，通过二次谐波产生研究了周期性极化纳米波导的非线性频率转换性能，测得归一化转换效率为1720%W/cm，接近理论值的60%。这项工作中描述的制造技术将为高效、低损耗铌酸锂非线性光子器件的发展铺平道路。
