Research On Integration Of Semiconductor Single-photon Detectors

Quantum information science is a new subject born from the combination of quantum mechanics and information science.Quantum communication is an important part of quantum information science.Based on Heisenberg's uncertainty principle and the non-cloning theorem of quantum mechanics,quantum secure communication provides a theoretically unconditionally secure communication method,which has been widely concerned around the world in recent years.In the quantum communication system,the single photon is used as the carrier of information and is transmitted in the quantum channel.As the terminal equipment,the single-photon detector becomes the crucial component,whose performance directly restricts the performance of the quantum communication system.So far,various single-photon detection technologies have been developed,among which semiconductor single-photon detector is the primary solution for practical applications due to the advantages of small size,low cost,and easy operation.The research and development of high efficiency and high integration semiconductor single-photon detectors are significant for practical quantum communication applications.The semiconductor single-photon detector has two core components:the single-photon avalanche diode and the corresponding quenching circuit,both of which have a fundamental effect on the performance of the detector.The key parameters for single-photon detector characterization include photon detection efficiency,dark count rate,afterpulse probability,maximum count rate,and timing jitter.In many applications,the photon detection efficiency is the most important one,which needs to be optimized specifically.This paper describes the author's research work in silicon and InGaAs/InP single-photon detectors in the direction of high efficiency and high integration during the doctoral period.In order to meet the requirement of performance comparison of single-photon avalanche diodes,a characterization platform for free-running silicon single-photon detectors and characterization platforms for low-frequency gating and 1.25 GHz sine wave gating InGaAs/InP single-photon detectors are built respectively to realize the automatic test of performances.For thick silicon single-photon avalanche diodes,a monolithic integrated circuit of active quenching and active reset is designed.By applying the circuit,a free-running silicon single-photon detector with ultra-high detection efficiency is designed.For InGaAs/InP single-photon avalanche diode,the photon detection efficiency reaches 60%at 1550 nm by performing structure design optimization and circuit operation parameters optimization.We design a monolithic integrated readout circuit and develop a miniaturized 1.25 GHz sine wave gating InGaAs/InP single-photon detector with ultra-high detection efficiency.At the same time,an integrated device with InGaAs/InP single-photon avalanche diode is studied.In these studies,the main innovations are:(1)For the requirements of multi-photon entanglement and quantum repeater,a monolithic integrated circuit of active quenching and active reset is designed to push the photon detection efficiency of thick silicon single-photon avalanche diodes to the upper limit.Compared with commercial products of single-photon counting modules(SPCMs),the relative increases of photon detection efficiency reach?8%.(2)We optimize the structure design and device fabrication of InGaAs/InP single-photon avalanche diodes with an additional dielectric-metal reflection layer to relatively increase the absorption efficiency of incident photons by?20%.With optimized gate amplitude and operation temperature,the SPD is characterized to reach a PDE of 60%at 1550 nm.(3)For the next generation of high rate quantum communication systems,we develop a miniaturized 1.25 GHz sine wave gating InGaAs/InP single-photon detector with ultra-high detection efficiency by applying a monolithic integrated readout circuit and the single-photon avalanche diode with high detection efficiency.