Design Of Photon Counting Readout Integrated Circuit For Avalanche Photondiode

In the field of weak light detection imaging,photon counting technology based on single photon avalanche photondiode(APD)response has been developed rapidly in recent years.It has been used in a wide variety of applications including Laser Radar,Spectral Measurement,Radio Detection and Quantum Key Distribution,with its high sensitivity,high signal-noise ratio and good time stability.However,with the constantly improvement of APD's array scale,photon detection efficiency(PDE)and sensitivity,the negative impact of the circuit such as non-uniformity,parasitic effect and noise interference has become more and more serious,the design of the corresponding readout integrated circuit(ROIC)has been more and more complicated which was seriously limits the application of large scale APD array.In this paper,a digital photon counting circuit based on passive sampling mode has been developed,which can integrated with 8 ×1 APD arrays operated in Geiger mode to count the photon distributed over a wide dynamic range.Fistly,this paper has expounded the principle of corona discharge photon detection and photon counting technology.To achieve a balance between the detection efficiency,range and power consumption,considering the design index demand and the characteristic of the existing system architecture,an passive sampling system architecture for random photon detection is proposed.And we have completed the design of system working procession and mode.Secondly,the completed prototype design of ROIC verify the feasibility of the system scheme based on the Modelsim simulation platforn.Finally,we have completed the design of circuit module,testability scheme,and system architecture.The ROIC circuit is fabricated by GSMC 0.35?m CMOS process,and simulated through the Cadence EDA tools.The working voltage of ROIC is 1.8V/5V,which supply the digital circuit and analog AQC circuit respectively.The scale of the ROIC array is 8 ×1 with each pixel's area of 60?×85p?m.The chip test results indicate that the ROIC is functional,the consistency of ROIC is usually more than 90%,and the relationship between the PDE of ROIC and the photon density is approximately piecewise inverse linearity.By adjusting the size of the dead time of APD,the PDF of the ROIC can reach 100%in low-light enviroment theoretically.The test results showed that the scheme of GM-APD-based photon counting ROIC was practicable,met the needs of the weak light sensor detection applications.