Research On Photon Counting Imaging Technology Based On APD

Get a clearer image in low light, low light level imaging system can make it a reality. With shimmer like to enhance the development of technology and low light level imaging devices, photon counting imaging technology in recent years to the rapid development and growing maturity. Theoretically photon counting imaging for effective detection of a single photon, and therefore able to detect the faint light photon image. Has a wide range of applications in the field of military reconnaissance, aerospace, space exploration, deep-sea exploration, biomedical prospects.In this paper, the core of the photon counting imaging devices avalanche diode (APD) research work in Geiger mode avalanche diode ((Avalanche Photodiode in Geiger Mode, GM-APD) with single-photon detection capability, high signal-to-noise ratio, The all-solid-state structure, transient response and low power consumption and unique pulse output characteristics. has become the hot spots in the field of low light level detection imaging, peripheral inhibition can not be directly used for the detection of a single photon avalanche diode laser pulse detection circuit for APD system provides a strong guarantee. performance a direct impact on the quality of the imaging detector. performance peripheral suppression circuitry to improve the signal-to-noise ratio of the system and the detection sensitivity. this article to through MATLAB and MULTISIM, software simulation given system optimization program. imaging laser radar-ray machine scanning system, there is a low frame rate, large size, and image distortion under high-speed conditions. however scan imaging system application area array avalanche diode (APD array) detector to obtain The distance of the target image and the the intensity like. simply detect target distance can be obtained image, so you can achieve a very high frame rate.From simulation experiments in this paper the following conclusions:the larger the amplitude of the gate pulse, easier in a very short period of time to trigger an avalanche, avalanche amplification ability more strong, but also amplifies the noise signal. To leave a certain interval between the gate signals, the gate turn-off time to be greater than the life of the capture of carriers, i.e., the APD voltage pulse duty not be too high, the repetition frequency should be relatively small. Designed preamp circuit heads magnified100times, reduce noise and improve the signal-to-noise ratio of the system. Based hamamatsu a S2382Model APD parameters design bandpass filter circuit band lower limit, paragraph the APD cut-off frequency of4KHz～100MHz, considering active bandpass filter circuit, front high-pass filter circuit design lower limit of the band4KHz, after low-pass filtering circuit design upper limit of the frequency band of50MHz, the system design requirements.