Research On Novel Silicon Photodetector And Its Test Method

With the rapid development of information technology and 5G,6G,Big Data,AI and other industries,the amount of data needed by human beings is growing exponentially,which poses a severe challenge to the speed of communication system.Optical interconnection has the advantages of frequency bandwidth,anti-interference,large capacity,low power consumption and so on.It is considered as the best solution to solve the bottleneck of electrical interconnection.It has become a consensus that optical interconnection technology based on silicon is the most concerned optical interconnection technology.Photodetector is one of the most important photoelectric converters in optical interconnection,which directly determines the transmission rate of optical interconnection system.Therefore,high-speed photodetectors and high-power photodetectors have become one of the hot spots.The work of this thesis mainly focuses on two research directions of photodetectors.On the basis of in-depth study on the principle of photodetectors,high-speed and high-power germanium silicon photodetectors are designed,simulated and manufactured.The detailed test methods of various parameters of photodetectors are studied,and the high-speed and highpower germanium silicon photodetectors are analyzed and summarized.The main work and innovation of this thesis are summarized as follows:(1)By using gain peaking technology,an inductor with appropriate inductance is integrated into the photodetector to improve the spectral response characteristics of the photodetector and effectively increase its bandwidth.As a result,the detector bandwidth is increased from 30.6GHz to 59.8GHz.A large signal test system is built to measure 100Gbit/s NRZ and 128Gbit/s PAM4 eye diagrams demonstrate the excellent high-speed performance of the photodetector.(2)A new type of photodetector with lateral coupling of silicon nitride waveguide is proposed.The saturated output power of more than 23 m A is achieved.The small signal test system is built.The bandwidth is 52.7GHz,39.2GHz,21.7GHz and 12.5GHz under 5m A,10 m A,15 m A and 20 m A output photocurrent,respectively.Under the high output current of 16 m A,the high-speed eye diagram of 60Gbit/s NRZ can still be obtained through large signal test,which proves the high-power and high-speed performance of the detector.(3)The testing principle and detailed testing method of various parameters of photodetector are studied and summarized.