The Electronic Circuit Design Of Compact Photon Counter

Photon counting technology has been widely used in various fields, and the derivativephoton counter can detect weak optical signals whose photon rate is less than108photonsper second. The technology used in photon counter includes photoelectric conversion, pulsediscriminating and number counting. Since the continued improvement in the developmentof large scale integrated circuit, the volume of photon counter has been greatly reduced, theapplications of photon counter become more widely.Firstly, based on the principle of photon counter, this thesis carried out a detailedfunctional division of its internal modules. By the analysis and research of the basic principleand characteristics of several optoelectronic detectors, it turns that the circuit design will bedifferent when using different optoelectronic detector. According to the range of application,complexity of the circuit design and counting frequency, we choose photomultiplier tube asthe detector of photon counter.We select the appropriate chip in accordance with the function of each circuit module,and ensure the value of each component by numerical simulations and analysis, then finishthe circuit design. The function of most part of the circuit is proved by the simulation ofMultisim software. Then, we test the actual circuits of each module in order, and design theprint circuit board after a successful test. SMD resistors and SMD capacitors have been usedin the circuit board. Finally, we take an entire test on the circuit board with input pulses ofknown repetition rate, get the number of pulses per second, and analyze the counting error.The photon counter’s volume of this project is10.29.72.4cm3, the maximal countingfrequency can reach to1MHz when the interval time of adjacent pulses get to the photoncounter is wider than1s.