重离子辐照KTP型晶体夹层光波导的制备及非线性倍频效应

As an important material processing and modification technology, heavy ion irradiation can effectively change the refractive index of optical materials, forming micro and even nano-scale waveguide structures. KTP-type crystals (KTP, KTA, RTP, etc.) have excellent nonlinear optical features and unique physical and chemical properties. Compared with bulk nonlinear materials, frequency-doubling devices based on waveguide structures theoretically have better SHG performance and higher conversion efficiency, which are compact in size and easy to integrate. In this project, we shall construct cladding waveguide (The core guiding region is located between two optical barriers) frequency-doubling devices in several KTP type nonlinear crystals on the basis of accurately modulating the refractive index of the crystals through the electronic damage induced by heavy ion (Ar, Kr) irradiation. The effects of irradiation ions on the structure and optical properties of materials will be studied from both micro and macro perspectives. We shall test transmission and SHG performance of such nonlinear waveguides to attain the optimized ion beam processing parameters. The coherence measurement of transmission and SH beams exited from the waveguides will be preliminarily carried out to explore the influence of heavy ion irradiation on the coherent properties of guided beams. The results would be positive to expand the application of ion beam technology in guided-wave optics. Meanwhile, the fabricated miniature cladding waveguide frequency-doubling devices would be promising in the field of integrated optics.

重离子辐照是一种重要的材料加工和改性技术，主要通过电子非晶损伤效应诱导光学材料的折射率发生变化，形成微米乃至纳米尺度的导波微结构。KTP型晶体（KTP、KTA、RTP等）具有优越的非线性光学和物理化学特性。基于光波导结构的非线性倍频器件与体块材料相比，理论上具有更高的能量转换效率，并且体积小巧，易于集成。本项目将针对几种KTP型晶体，在重离子（氩、氪）辐照电子损伤机制精确调制晶体折射率的基础上，构建“夹层型”（波导核心区域位于两个位垒之间）一维/二维波导倍频器件；从微观和宏观层面，研究辐照离子对材料结构和光学性能的影响；测试波导的传输、倍频性能，得出最优化的离子辐照条件；并初步开展波导中传输与倍频光束的相干度测量，探究重离子辐照条件对波导光束相干性的影响。研究结果有助于拓展离子束加工技术在导波光学中的应用。同时，所制备的微型“夹层”波导倍频器件，在集成光学领域有广阔的应用前景。

离子辐照是一种重要的材料加工和改性技术，能诱导光学材料特定区域的折射率发生变化，形成微米乃至纳米尺度的导波微结构。KTP型（KTP、KTA、RTP等）晶体具有优越的非线性光学特性和独特的物理化学性质。基于波导结构的非线性倍频器件与体块材料相比，理论上具有更优异的倍频性能和更高的转换效率，并且体积小巧，易于集成。本项目在充分认识离子辐照电子能量损伤改性晶体折射率机理的基础上，着重研究了高能氩离子对YAG晶体折射率调制的实现和“夹层型”波导的建构；中等能量碳、氧离子辐照非线性晶体数微米尺度的频率转换器件的形成与性能表征；离子注入KTP晶体上非线性跑道型微环谐振器的制备与谐振模拟分析；基于BIC机制的离子注入非线性晶体波导的制备与传输特性模拟。从微观和宏观层面，揭示了入射离子对材料结构和光学特性的影响；通过优化离子束加工条件、辅助加工手段、波导结构和形貌特征，有效地提升了波导的传输和非线性频率转换性能。