Study On Single-photon Detector Based On CMOS Technology Single-photon Avalanche Diode

Optical signals will disperse into photons when it is extremely weak,be called as single-photon signal.As its weak intensity and significant particles,Single-photon is hard to detect by conventional means testing and considered to be the limit of the photoelectric detection technology. But, single-photon as a kind of widespread information carrier has been highly regard and widely applied in the daily life,industrial production,scientific research and military areas.Single-photon detection technology is mainly manifested in the following respects: single photon detector with a very high gain,extremely fast circuits to control the single-photon detector and processing single,integration of devices and circuits,accomplishing large-scale array.There are a series of problems to be solved in practical application.The characteristic of single-photon detector is poor in technology,working voltage,price,repeatability.Circuits work slow and take much layout.The hybird integration of devices and circuits easily lead to performance degradation and noise enhancement.This article with support of the central colleges and universities scientific research basic business finding researched single-photon detection technology to solve the above problems.The paper put forward to use CMOS technology avalanche photodiode with protection ring as single-photon detector and introduced its working principle and characteristic parameters.The paper used the equivalent circuit model instead of avalanche photodiode in the circuit simulation,compared three kinds of quenching model and selected active quenching circuit controlling avalanche photodiode,designed high speed voltage comparsion circuit screening avalanche signal,planned two counting circuit.As an important work,we constructed an complete pixel circuit,including the equivalent circuit of avalanche photodiode, the quenching and resetting circuit, avalanche signal discrimination circuit,photon counting circuit,etc.The simulation results show that the minimum detection time is 5ns,dead time of quenching circuit is approximately 2.690 ns,the time from photon into detector to accomplish counting last 3.0572 ns,counting in linear mode range from 0 to55.In addition,paper introduced the principle and circuit structure of time correlated single photon counting,applied voltage comparator defining time of photon arriving,stated several typical kinds of time to digital converter,designed two types time amplifier circuit based on S-R lanch and current bias ratio.