介电体光波导中的非线性光学效应及光子集成研究

In the proposed project, we will concentrate on developing the nonlinear couple mode theory, and the material system we studied is dielectric optical waveguide, such as lithium niobate waveguide et. al. We will focus our study on the nonlinear optical effects and complex coupled-wave processes in single multi-mode waveguide as well as coupled waveguide systems. Based on the above research, we will further develop novel integrated light sources and nonlinear functional devices with modulating characteristics based on nonlinear couple-mode theory. On the experiment aspect, we aim to further improve proton-exchange, Ti-diffusion, and micro-machining techniques (including femto-second laser writing and reactive ion etching) to produce high quality dielectric optical waveguide for realizing novel optical effects and functional devices. To sum up, we hope to provide theoretical instructions and technical support to the novel nonlinear photonic integration devices via implementing this project.

本项目以铌酸锂介电体光波导为材料体系，立足于发展波导中的多模非线性耦合理论，重点开展单根和多根耦合波导体系中的非线性光学效应及复杂耦合波过程的研究。在此基础上，探索开发基于非线性多模耦合理论的新型集成光源和具有调制特性的非线性光子集成功能器件。在实验上，进一步发展质子交换、钛扩散和微加工（包括飞秒激光刻写和反应离子刻蚀）等波导加工技术，制备出高质量的波导并实现介电体材料光波导中的新颖光学效应和功能器件。期望通过项目的实施，为今后开发新型的非线性集成光学元器件提供理论指导和技术基础。

本项目在非线性波导的制备工艺，以及非线性集成光子学方面取得了系列进展。我们发展并优化了质子交换和钛扩散波导的制备工艺，做到了波导模式可控，建立了一套完整的波导表征和测试系统，波导传输损耗控制在0.3~0.5dB/cm，接近国际先进水平。我们在周期极化超晶格波导中实现了背向倒格矢调制的非线性Cherenkov差频辐射，还将相位匹配方式从QPM拓展至BPM，在双折射晶体KTP中实现了非线性Cherenkov差频辐射，类似的思路可以进一步推广到波导中的模式匹配。我们将腔相位匹配的思想引入到杂化波导中spp的非线性放大器设计上，设计出微米量级的spp放大器。此外，作为拓展研究，我们在项目的支持下还开展了光的非线性成像、聚焦，以及结构光束的非线性频率转换研究。