飞秒激光写入钽铌酸钾晶体光波导的制备及其特性与应用研究

Femtosecond laser inscription (FLI) has recently emerged as an efficient and mature technique for micromachining of optical crystals. Localized refractive-index changes can be created in minuscule spatial scale by utilizing the FLI. Based on the formation of the waveguide structures, integrated waveguide devices with multiple functions and can be achieved. Owing to its excellent dielectric, ferroelectric, piezoelectric and electro-optical properties, potassium tantalum niobate (KTN) crystal has attracted a lot of attention in the fields of functional materials now. In this project, we will utilize FLI to fabricate various types and multi-dimensional waveguide structures, and fulfill the electrically controlled beam deflection and scanning. Meanwhile, we will develop “fiber-waveguide-fiber” device modules integrated with the fiber. Here, the modification on the materials induced by femtosecond laser will be explored, and the physical mechanisms and the regulative rules will be illustrated. The refractive index distribution, propagation properties as well as the electric-controlled beam deflection and scanning features will be investigated in order to obtain integrated devices. The research of this project will enhance the scope of FLI applied to crystal micromachining, and the waveguides structures and guiding devices in KTN crystal which have broad applications in various of fields, including integrated optics and modern communication.

飞秒激光写入技术是一种高效、成熟的晶体材料微纳加工技术，能够在极小的空间尺度内改变材料折射率，形成光波导结构，进而实现多功能化、可集成化微型光波导器件。钽铌酸钾晶体具有优越的介电、铁电、压电以及电光性能，是当今功能材料领域的研究热点。本项目利用飞秒激光写入技术在钽铌酸钾晶体中制备多种类型、多维度的光波导结构，并基于材料的电控光束偏转、扫描特性实现波导器件电光调制中功能；同时，结合光纤，研发“光纤-波导-光纤”型可集成化波导器件模块。项目首先将探讨飞秒激光对晶体材料的改性作用，揭示其物理机制，阐明调控规律；系统研究光波导结构的折射率分布、导波特性，深入研究波导电控光束偏转与扫描性能，并研发可集成化微器件。项目的研究将扩大飞秒激光写入技术在晶体材料加工中的应用范围，促进钽铌酸钾晶体光波导在集成光学、现代通信等领域中的应用，研究价值极高，应用前景广阔。

飞秒激光写入技术是一种高效、成熟的晶体材料微纳加工技术，能够在极小的空间尺度内.改变材料折射率，形成光波导结构，进而实现多功能化、可集成化微型光波导器件。钽铌酸钾晶体具有优越的介电、铁电、压电以及电光性能，是当今功能材料领域的研究热点。本项目利用飞秒激光写入技术在钽铌酸钾晶体中制备多种类型、多维度的光波导结构，并基于材料的电控光束偏转、扫描特性实现波导器件电光调制中功能；同时，结合光纤，研发“光纤-波导-光纤”型可集成化波导器件模块。研究过程中，首先探讨了飞秒激光对晶体材料的改性作用，揭示其物理机制，阐明调控规律，为飞秒激光加工钽铌酸钾晶体参数窗口的建立奠定了基础；其次成功制备了脊型光波导、双线型光波导和包层光波导结构，并系统研究了光波导结构的折射率分布、导波特性，深入研究波导结构分别在温度场调控和外加电场调控情况下的光学特性表现，对导波模式、导波偏振特性以及导波传输损耗等特性进行了详细的探究，结果表明外场调控下的导波模式具有一定选择性，可实现支持不同传输模式的激光传输，以及具有不同偏振特性的激光传输。项目的研究将扩大飞秒激光写入技术在晶体材料加工中的应用范围，促进钽铌酸钾晶体光波导在集成光学、现代通信等领域中的应用，研究价值极高，应用前景广阔。