MPPC And Its Application In Laser Ranging

Multi-Pixel Photon Counter(MPPC),also known as Silicon Photomultiplier(SiPM),is a kind of weak light detector,which can respond to single photon.Otherwise,the most outstanding feature of the detector is having a good resolution to single-photon.The structure of MPPC is composed of tens to thousands of G-APD units,those units are integrated on the same silicon chip in parallel and share one electrode to output.Among them,each one is connected with a large resistance of hundreds of thousands of ohms in series,those resistances are mainly used for quenching.MPPC has some excellent characteristics,such as sensitive to weak light,can distinguish single photon,small in size,easy to integrate with devices,not easy to be interfered by magnetic field,low in cost and etc.Therefore,MPPC has become a research hot spot in the field of weak light detection,mainly used in nuclear physics,topographic and geomorphological exploration,medical imaging,laser ranging and so on.The main work and results of this paper are the following parts.1.The characteristics of the photoelectric properties and the ultra dynamic range of MPPC are described.It founds that the The ultra dynamic range cannot be explained by the traditional theory.In view of this problem,this paper makes a detailed theoretical derivation,and gives a reasonable explanation,and guesses this phenomenon may come from where exists a small gain in the dead,and the value may be around at 250.2.Having researched the portable MPPC module.There are a lot of researches on MPPC abroad,but there are few researches in China,mainly because MPPC integrated modules need to be imported.The cost of importing one is tens of thousands yuan,and the price is to dear to apply in many fields.In view of this problem,the laboratory developed portable MPPC module,which costs only one or two thousand yuan,and its functions are equivalent to those importion.The portable module is conductive to promoting the research of MPPC in many fields.3.The portable MPPC module is applied in laser ranging.The MPPC is used widely in many fields,this paper mainly carry out the portable MPPC module developed from our laboratory in laser ranging,and improve the signal-to-noise ratio of MPPC by some means.Building a set of laser ranging principle diagram,and combining with the technique of TCSPC.Multi-target measure comes ture at last,and the range accuracy of mm level be achieved.It is equal to the imported laser rangefinder.The innovation points of this paper are the following parts.1.Explaining the ultra dynamic range of MPPC and giving a reasonable explaintion for the first time;2.The portable MPPC module is developed for the first time in China;3.Multi-target laser ranging can be realized at the same time,and the signal-to-noise ratio can be improved by increasing the p.e.threshold of MPPC.