The Research Of Silicon Avalanche Photodiode Single Photon Detector On Space Quantum Communication

In the past two decades,single photon detectors have been widely used in space applications as key devices,such as laser ranging,laser time transmission,space irradiation detecting,scintillation detecting of elementary particles and deep space optical communication.Due to the high vacuum and high radiation environment in space,the single photon detectors must have high reliability and radiation resistence,especially for space quantum applications,such as space quantum teleportation,space entanglement-based quantum key distribution etc.,which need high signal-to-noise receiving system.At present,the most common single photon detectors include PMT(PhotoMultiplier Tube)single photon detector,APD(Avalanche PhotoDiode)single photon detector,up-conversion single photon detector and superconducting nanowire single photon detector.Compared with the PMT single photon detector low detection efficiency(only about 10%near 800 nm wavelength),the up-conversion single photon detector complex photoelectric system and the superconducting nanowire single photon detector complicated refrigeration equipment,the cheap and compact APD-based single photon detector with low dark count,high detection efficiency(about 60%near 800 nm wavelength)is more suitable for space applications.In space radiation environment,the silicon APD single photon detector dark count will keep increasing due to radiation damage.At present,the reported best in-orbit silicon APD single photon detector radiation-induced dark count incremeant rate is about 50 cps/day,which can not meet the requirements of space quantum communication.With the development and commercial application of optical fiber and ground free space quantum communication,satellite-based space quantum communication has attracted much attention because it can overcome the the Earth curvature limitation without quantum relay and realize the unconditional safe information transmission between any two points on the earth.Based on the global satellite-based quantum communication,this paper systematically researches the silicon APD single photon detector,including the radiation effects on the silicon APD single photon detector performance,radiation protection measures and how to improve the receiving system signal-to-noise rate.Then the spaceborne silicon APD single photon detectors with high radiation resistance and the high-performance silicon APD single photon detectors with large photosensitive area have been implemented and they have played a very important role in the mission of Micius Quantum Science Experiment Satellite,and their performance and reliability have been verified.Firstly,the possible in-orbit radiation effects on the silicon-based single photon detectors are analyzed and are verified using the high-energy protons produced by the accelerator,the performance degradation of the silicon APD single photon detectors under different radiation dose is evaluated.Aiming at the silicon APD single photon detectors radiation-induced dark count rate performance degradation,the measures to improve the silicon-based single photon detectors resistance performance,such as metal shielding,lowing operating temperature,high temperature annealing etc.are researched.Secondly,aiming at the detector requirements of Micius satellite mission,space-borne silicon APD single photon detectors have been designed and implemented,including high voltage management,temperature control,installation structure etc.After the launch of the Micius satellite on August 16,2016,the space-borne silicon APD single photon detector as a key device has participated in the satellite-to-ground quantum teleportation experiment,satellite-to-ground entanglement distribution experiment and other scientific missions.At the same time,we have carried out a long-term test of the in-orbit performance of the space-borne silicon APD single photon detector.After nearly two years in-orbit performace testing,the space-borne silicon APD single photon detector has achieved a superior in-orbit dark count increment rate,about 0.56 cps/day.Finally,towards the high satellite-to-ground links attenuation challenge for quantum communication,a high performance detector based on large photosensitive area silicon APD is designed and implemented to improve the ground receiving system efficiency.At the same time,by lowering the operating temperature and increasing the bias voltage,a high efficiency single photon detector based on SLik silicon APD is realized.Compared with the SPCM-AQRH-13 commercial SLik silicon APD single photon detector,the detection efficiency of our SLik silicon APD single photon detector is about 10%higher.The key innovations of this paper are listed as follows,1.According to the SLik silicon APD dark count performance degradation level at different radiation doses and the effectiveness of radiation protection measures,the SLik silicon APD in-orbit dark count growth rate is predicted accurately,about 0.89 cps/day.2.A high reliability spaceborne silicon APD single photon detector with high high radiation resistence is designed and implemented.Through the long-term in-orbit test in the past two years,the spaceborne silicon APD single photon detector has achieved a very low in-orbit dark count increment rate performance,about 0.56 cps/day,which is about 2 orders of magnitude lower than the reported best in-orbit detectors.3.A low cost,low dark count and blindness attack monitoring capacity single photon detector with large photosensitive area silicon APD and a high detection efficiency single photon detector based on SLik silicon APD were implemented.