Silicon Photoelectric Detector Characteristics Analysis And Experimental Research

With the continuous development and utilization of new energies and new technologies, the research of light energy has entered a new stage. In1930s, light detection is based on the usage of the photomultiplier tubes (PMT). They are expensive, and their internal mechanical structures in the vacuum space are complicated to manufacture, also the volume of them are large and the most important issue is that they are sensitive to electromagnetic interference. After that, people began to search new alternatives to study the light. Along with the rapid developments in the semiconductor industry, the photosensitive semiconductor devices, like a silicon PIN photodiode, avalanche diodes, and silicon photomultipliers which were invented1990s, have been developed rapidly. In many areas they have already replaced the PMT, and as might be expected that the semiconductor detectors will be more widely used in the future. The silicon photomultiplier is considered as the most promising one, because it has a very high gain, even without the need an external amplifier, and it is made in an economical and effective way by standard CMOS processing. Besides the application in radiation measurement, silicon photomultiplier is attracting widespread interest in the medical field, like Positron Emission Tomography (PET). PET is the new and the only imaging technology which shows the vivo metabolism of biological molecules, the activity of receptors and neurotransmitters, but its lack of scanning between the fault planes. Magnet Resonance Imaging (MRI) can fulfill this purpose. MRI is a Bio-magnetic spin imaging technology which can make all kinds of tomography images. It does not produce artifacts during the CT test, no ionizing radiation and without adverse effects on the human body. If PET and MRI can be combined together, it will play a far-reaching significance for medical research and development. However, the light detector used for PET is PMT and PMT is unable to work in a strong magnetic field. This limits the usage of PMT itself with MRI. But the silicon photomultiplier can just solve this problem. It makes it possible to combine PET with MRI.The first step of this thesis work is purchasing the different photodetectors. One PIN photodetector and two avalanche photodetectors are bought from Hamamatsu in Germany, and one cost-effective silicon photomultiplier is bought from SensL in Britain. Next is to set down the basic experiment configuration. The optical neutral density filters and the laser output power drove with two power sources are calibrated. The last part of the experiment is testing the three different photodetectors which measure the weak output light intensity transferring through the optical neutral density filters, this paper will compare the differences between them, show some of their characteristics respectively and look for their detection limits. Finally based on the detection limits and the simulation results of the attenuation from the hollow waveguide, the longest length of the hollow waveguide is given. In the present experimental conditions, the maximum length is about3.5meters. At last, a conclusion is given and some improvements are also noted.Recently Excelitas Technologies announced that their company has achieved the world record high photon detection efficiency (PDE) with low dark count performance in the development of solid state silicon photomultiplier (SiPM) technology.