基于自耦合谐振的硅基可编程微波光子信号处理芯片研究

Silicon integrated programmable microwave photonic signal processor, where a common hardware platform, is reconfigured by software to perform a multitude optical signal processing task like delay, filtering and phase shifting, brings greater reductions in space, power and cost, and also increases system robustness and flexibility. It has wide applications in wireless communication, defense electronic equipment, etc. .To push this technology further towards practical use, there are still some fundamental scientific problems to be overcome, including key elementary component and topology architecture design, control algorithm implementation based on simultaneous optical power feedback. Therefore, this project will be based on our own intellectual property namely cascaded self-coupled optical waveguide (SCOW) resonators, and investigate low power tunable couplers, phase shifters and variable optical attenuators to construct chip topology architecture. By utilizing surface state absorption (SSA) effect, on-chip simultaneous optical power monitoring and feedback is established. To software-defined automatic control of the processor, the project will also build a mathematical model of the chip based on transfer matrix method, and use matrix calculation to inverse derive the parameter of every tunable element. After that, the project will fabricate a prototype chip using CMOS compatible processes, and experimentally demonstrate it..The results of this research will propel the practical application of the programmable optical signal processor, and provide technical support to the sustainable development of integrated microwave photonics and relevant industry of our country.

硅基集成可编程微波光子信号处理器是在同一硬件平台上，通过软件编程重构光路来实现延时、滤波、移相等光信号处理功能，能大幅度降低系统体积、功耗和成本，提高系统鲁棒性和灵活性，在无线通信、国防电子装备等领域具有重要应用。为推动这项技术尽早走向实用，需要解决核心单元器件和拓扑架构设计、基于实时光功率反馈的控制算法实现等关键科学问题。本项目以具有自主产权的级联自耦合谐振结构为核心，通过研制低功耗可调耦合器、移相器、光衰减器等单元器件，构建芯片拓扑架构；基于表面态吸收实现片上光功率实时监控和反馈；基于传输矩阵法建立芯片数学模型，利用矩阵计算反向推导每个可调单元的参数，实现编程自动控制；采用CMOS兼容工艺制备原型芯片，并开展实验验证。项目成果将推动硅基可编程光信号处理芯片的实用化，为我国在集成微波光子芯片和相关产业的可持续性发展提供技术支撑。

在项目执行期中，对设立的研究内容进行了研究和探索。成功研制了3级基于SCOW结构的硅基可编程光子信号处理原型芯片，该芯片可以实现数字可调延迟线、微环滤波器、非对称MZI滤波器、FP滤波器等多种类型的光子处理器结构，到了项目所设立的指标。此外，将SCOW结构进行二维拓展，可以实现酉矩阵变换器功能，在量子计算、神经网络等方面具有广泛应用。.利用MZI作为可调耦合器结构，在氮化硅平台上实现了可重构微波光子滤波器，可以实现微波光子带通和带阻滤波器，并且滤波中心频率和带宽都可调。利用MZI作为光开关进行光学路径选通，实现可调光延迟线，并以此在硅基平台实现了首个8通道微波光子波束成形芯片，相关工作发表在Optica上。.在器件性能优化方面，优化了可调耦合器的损耗，并以此实现了硅基4x4光开关芯片，三级MZI结构的损耗为1.74 dB。在自动控制算法方面，提出利用机器学习算法从传输谱线中提取器件参数，从而进行反馈调节实现状态校准。.该成果得到了国际同行的认可，多次受邀在PIERS，OECC等会议进行口头报告。共发表12 篇SCI 论文，申请4 项发明专利，培养硕士研究生2名，博士研究生1名。.在以上成果的支持下，申请人进一步得到了2021 年自然科学基金面上项目(6207030193)的资助，将继续研究利用硅基可调耦合器结构来实现多种不同功能的光子芯片。以上工作将为我国集成光电子芯片真正走向实用化，并服务于我国芯片、大数据和国防等重大需求提供技术支撑。