| The technology research of night-vision imaging and detection in low light condition is always the research emphasis for all the national military reconnaissance. For fast dynamic detection and identification of target signals in low light conditions, EMCCD has unique advantage, and its detection sensitivity can reach the standard of real single photon event detection.With the advantages of EMCCD in high sensitivity detection capability、high reliability, long life, low cost and easy system miniaturization and digitization、large dynamic range detection by controlling the multiplier voltage intelligent, it has been widely used for low-light imaging and detection at home and abroad. However, the using of EMCCD in low-light situation decides that its output signal is weak and mixed with noise. And in EMCCD imaging system, as for the digital signals have larger noise margin and smaller risk to be interfered, so, whether the design of analog front-end is successful or not decide the signal-to-noise ratio of the entire EMCCD camera.For the real-time applications of EMCCD imaging systems in low light environments, according to the strict requirements of the EMCCD drive signal on phase、frequency、 amplitude, and the characteristics of the output signal, basing on the in-depth analysis about the analog front-end features, we proposing a strategy that improving the EMCCD driver circuits、optimizing the EMCCD drive signal quality,reducing the noise level in EMCCD analog front-end,to design a real-time, low noise, high signal-to-noise ratio EMCCD camera which can work in low light environmental.Testified by projects, EMCCD camera has real-time and high-speed imaging capability, and when the signal clock is12.5MHz,the image data rate is25frames per second, ambient illumination is1×10-3Lx, the output signal is stable and low noise, the captured images are clear、stable and have higher signal-to-noise ratio, basically meets the using requirements of EMCCD camera in low light environments. |
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