第317期“工物学术论坛”
报告题目：Silicon single-photon avalanche diodes with ?nano-structured light trapping
报 告 人：臧凯，灵明光子（Adaps ?Photonics），CTO
报告时间：2019年2月28日（周四）下午2:30—4:30
报告地点：清华大学刘卿楼104教室
主 ?持 人：邓智 副教授

报告摘要：
Single-photon detectors are known for high sensitivity and ?picosecond timing resolution (i.e., low jitter). They have been widely ?used to push the frontiers in both academic research and industrial ?products for depth sensing (e.g., LiDAR), quantum key distribution, ?single-molecule fluorescence, and bio-medical imaging. Among ?single-photon detectors, Si-based SPADs have gained interest due to ?their low cost, compact form factor, ease of integration, and ?compatibility with standard CMOS fabrication techniques. However, in ?the near-infrared regime of interest (750 nm to 1 μm in wavelength), ?these devices suffer from a clear trade-off between the detection ?efficiency and jitter due to low optical absorption in ?silicon.
To break this trade-off, I will demonstrate a Si-SPAD ?design with nanostructures to provide light trapping. In my talk, I ?will start with an overview of the physics behind the efficiency and ?jitter of SPADs, and then show simulation and experimental results of ?my light-trapping SPADs, which were fabricated in the Stanford ?Nanofabrication Facility (SNF). Finally, I will show how my device ?compares to other Si-SPAD designs in literature.
In addition, I ?will demonstrate improved efficiency of Si-SPAD in the ultraviolet ?wavelength regime by creating a graded doping profile to better ?collect carriers generated on the surface. After this, an imaging ?application for SPADs is demonstrated, where we record the transient ?imaging of light propagating within objects on a 300ps timing ?scale.
报告人简介：
Kai Zang received the Diploma from Peking ?University, the M.S. and the Ph.D. from Stanford University in 2011, ?2013, and 2017, respectively, all in electrical engineering and EECS. ?He was with Microsoft Hololens Group from 2017 to 2018, where he was ?the optical engineer for the next generation augmented-reality (AR) ?display and sensing technology. He is now the co-founder and Chief ?Technology Officer of ADAPS Photonics. His research interest span from ?Single Photon Detector, Ge SPP (Surface Plasmon Polariton) based ?meta-material, Si/Ge QCSE (Quantum Confined Stark Effect) on chip ?optical interconnect system.