面向晶圆级集成光子收发回路的片上在线高频测试基础研究

On-wafer in-line testing is considered as an essential enabling technology for wafer-level in-line inspection in the high-density photonic integration. The conventional chip testing methods require to be probed with an off-chip optical-to-electrical (O/E) or electrical-to-optical (E/O) transducer, and need extra intense O/E or O/E calibration to remove the transducer impact in the measured frequency response. For realistic wafer-level in-line inspection, we investigate in this project the in-line high-frequency characterization technology with the capability of O/E or E/O self-calibration. An on-wafer characterization method based on two-tone photomixing mapping will be presented. The theoretical models in the optical modulation and detection will be established between the two-tone optical spectrum and photomixing electrical spectrum. Research emphasis will then be put on how to cancel out the effect of O/E conversion in the optical modulation mapping, how to realize the equalization of E/O modulation in the photodetection mapping in order to verify the proposed method with self-calibration capability. Our research is believed to provide a useful reference for realizing automatically in-line inspection of high-density integrated photonic wafer.

晶圆级片上在线测试是高密度光子集成的支撑性技术，传统光子芯片测试方法存在片外光耦合和额外电/光或光/电校准的缺点。本项目面向晶圆级集成光子收发回路研究具有电/光和光/电片上自校准的在线高频测试技术。提出基于双音混频映射的片上测试方法构，利用双音混频映射原理分别提取光调制器和光探测器的本征频响，实现电/光和光/电片上自校准测试方案原理验证，为高密度集成晶圆级自动化在线检测奠定基础。

晶圆级片上在线测试是高密度光子集成的支撑性技术，传统光子芯片测试方法存在片外光耦合和额外电/光或光/电校准的缺点。本项目面向晶圆级集成光子收发回路研究具有电/光和光/电片上自校准的在线高频测试技术。采用半导体光放大器的级联四波混频效应产生获得了宽带可调的光学频率梳，并通过光子混频将光域光谱映射到电域频谱，作为方案验证，光谱-电谱映射实现了超宽频带、高精度的微波信号频率测量，测量误差0.2MHz以内。基于光谱-电谱映射原理，利用低重频的被动锁模激光器（重复频率100MHz）作为频率梳，将光域光谱变换到电域低频电谱，借助低频光电探测器和低带宽的频谱分析仪（带宽100MHz），即可实现对40GHz宽带电光强度调制器的幅频响应的高精度测量，且无需额外对光电探测器频响进行校准。基于光谱-电谱映射原理，利用低重频的被动锁模激光器（重复频率100MHz）作为光学频率梳，将光域光谱分别映射到电域电谱，借助低频微波源和低带宽电光调制器（带宽1.5GHz），实现了30GHz宽带光电探测器的响应度高分辨测量，且无需额外对电光调制器频响进行校准。采用双音光谱-混频电谱映射原理，率先演示并实现了具有电/光和光/电自校准能力的片上高频测试，带宽30GHz。项目资助期间，发表SCI/EI论文10篇，其中SCI二区论文4篇，申请专利2项、授权6项，项目组成员在国际会议做特邀报告7次。项目研究为高密度集成晶圆级自动化在线检测奠定基础。