片上集成偏振分析仪关键技术及器件研究

The accurate and high efficient measurement for polarization state is important in high speed coherent fiber optics communication, fiber sensing and quantum communication. However, the current polarization analyzers are based on discrete and complex devices and components, which are disadvantageous for the measurement of sensitive parameters and cannot accommodate the new trend and new techniques in fiber optic communication system. In this project, the mechanism of polarization conversion, coupling and mapping between different waveguides will be investigated, as well as the polarization handling in Silicon nano waveguide. For this purpose, the on-chip functional blocks with desired transmission matrices will be established, and the polarization crosstalk and maintaining will also be studied. Based on the optical and electronic models, the high speed and polarization insensitive detecting scheme will be designed to measure the optical power after splitting and polarization handling. As a result, the Stocks parameters can be deducted, meaning the state and degree of the polarization can be further obtained. The project will be performed through theoretical analysis, device design/fabrication and chip characterization and testing. An integrated on-chip polarization analyzer will be proposed and demonstrated. Furthermore, more robust scheme for polarization analysis, which can accommodate future communication systems utilizing new techniques, can be expected.

偏振态的高效准确检测在高速相干光纤通信、光纤传感和量子保密等领域有着广泛而重要的应用。现有偏振分析仪均是基于分立复杂元器件，不利于偏振态这种敏感参数的测量，且无法适应光纤通信发展新趋势和新技术。本项目拟在探索不同波导之间偏振态等效转换、耦合和映射机理基础上，深入研究硅基纳米波导中偏振调控机理，构建片上具有不同传输矩阵的功能单元器件，分析过程中偏振保持及串扰问题。从光学和电学模型出发，设计偏振无关、高速片上探测方案来测量分割及调控后的光功率，反推出入射偏振光的斯托克斯参数，得到完整的偏振态及偏振度等表征。从理论分析、器件设计和工艺制作、测试验证三方面出发，提出集成片上偏振分析仪解决方案，实际制作出芯片原型。进一步探索适合于偏振复用和模式复用等新技术的片上偏振分析方案。

偏振测量广泛的应用于军事、医疗、科技以及日常生活中，如大气、海洋、深空探测；病情诊断、生物检测；光纤通信、传感等。目前的商用偏振分析仪都是基于波片、光纤等分立器件组合而成，体积大、成本高、稳定性差。本项目从理论分析、器件设计和工艺制作、测试验证三方面出发，提出并制作了硅基集成片上偏振分析仪。建立了光纤中任意偏振态和Si基纳米波导中等效偏振态的转换和映射模型，解决了自由空间/光纤中和平面波导之间的偏振失配问题；深入研究了片上偏振操控机理，构建了具有合适Muller矩阵的新型偏振调控器件单元，利用超小型器件单元获取了完整斯托克斯参量；设计了高线性度、高响应度光电探测器，将光信号转成电信号进行分析。.通过微纳器件加工和硅锗异质集成的方法，实际制作出了CMOS兼容的集成片上偏振分析仪芯片(1mm×0.3mm)，并封装成可直接使用的样机(45mm×50mm×90mm)。开发了可视化软件，能实现超高速大容量相干光纤通信中任意偏振态的高速测量，并在电脑上实时显示。进一步应用于实际链路中偏振模色散测量，得到了精确测量结果。在理论和方法上实现一定程度创新，良好的完成了研究目标。.设计制作出的集成偏振分析仪响应速度快，结构紧凑，稳定性高，使用方便，成本低，为快速精确的偏振态测量提供了一个良好的解决方案。一定程度上展示了我国在原创性科研仪器研究方面的进步，提高了基础科学研究在国际竞争中的地位和潜力。