Zhou Haitao, He Xiaoling, Wu Wenyuan, Tong Jingfang, Wang Jinliang, Zuo Yanbin, Wu Yicheng, Zhang Changlong, Hu Zhanggui
Tianjin Key Laboratory of Functional Crystal Materials, Institute of Functional Crystals, School of Materials Science and Engineering, Tianjin University of Technology, 300384, Tianjin, China.
Guangxi Key Laboratory of Superhard Materials, China Nonferrous Metals (Guilin) Geology and Mining Co., Ltd, 541004, Guilin, China.
Light Sci Appl. 2023 Jan 12;12(1):23. doi: 10.1038/s41377-022-01022-0.
"New" electro-optical (EO) crystals are hard to find, "old" EO crystals are scarce and each has its own problems, and the demand for high-performance EO crystals by higher power, higher repetition rate, and narrower pulse width laser is realistic and urgent. The EO performance of KTP was recognized as soon as it was discovered, but after more than 40 years of development, the reports, and products of EO devices based on KTP are less than those of other EO crystals, even though KTP is now almost the cheapest nonlinear optical crystal material. In this paper, based on our understanding of the crystal structure of predecessors and ourselves, especially the understanding and practice of quasi-one-dimensional ionic conduction mechanism, we think that crystal growth is the most important reason that affects the controllability of crystal performance. Through a series of science and technology, we realize the growth of large-size crystals with high-optical uniformity, then reduce the absorption of KTP to a very low level, and grow crystals with resistance to electric damage and laser damage. On this basis, reducing the conductivity and improving the uniformity of optical, electrical, piezoelectric, and ferroelectric properties are emphasized. The extinction ratio, piezoelectric ringing effect, and thermal influence of the EO switch based on KTP crystal are tested, and some publicly available progress of using KTP EO devices in high-repetition rate laser is listed. Finally, we are looking forward to the development of KTP EO crystal for the laser system to EO generator for integrated optics.
“新型”电光（EO）晶体难以寻觅，“旧型”EO晶体也很稀缺，且每种都有自身问题，而高功率、高重复频率和窄脉冲宽度激光器对高性能EO晶体的需求既现实又迫切。KTP一经发现其电光性能就得到了认可，但经过40多年的发展，基于KTP的电光器件的报道和产品却比其他EO晶体少，尽管KTP现在几乎是最便宜的非线性光学晶体材料。在本文中，基于我们对前人及自身晶体结构的理解，尤其是对准一维离子传导机制的理解和实践，我们认为晶体生长是影响晶体性能可控性的最重要原因。通过一系列技术，我们实现了具有高光学均匀性的大尺寸晶体的生长，然后将KTP的吸收降低到非常低的水平，并生长出抗电损伤和激光损伤的晶体。在此基础上，着重降低电导率并提高光学、电学、压电和铁电性能的均匀性。测试了基于KTP晶体的电光开关的消光比、压电振铃效应和热影响，并列出了在高重复频率激光器中使用KTP电光器件的一些公开进展。最后，我们期待KTP电光晶体从激光系统发展到集成光学的电光发生器。
