Dou Jiangpei, Niu Bingli, Zhao Gang, Zhang Xi, Wang Gang, Yuan Baoning, Wang Di, Qian Xingguang
Nanjing Institute of Astronomical Optics & Technology, Chinese Academy of Sciences, Nanjing 210042, China.
CAS Key Laboratory of Astronomical Optics & Technology, Nanjing Institute of Astronomical Optics & Technology, Nanjing 210042, China.
J Imaging. 2025 Jun 18;11(6):203. doi: 10.3390/jimaging11060203.
The wavefront sensor (WFS), equipped with an electron-multiplying charge-coupled device (EMCCD) detector, is a critical component of the Cool Planets Imaging Coronagraph (CPI-C) on the Chinese Space Station Telescope (CSST). Precise calibration of the WFS's EMCCD detector is essential to meet the stringent requirements for high-contrast exoplanet imaging. This study comprehensively characterizes key performance parameters of the detector to ensure its suitability for astronomical observations. Through a multi-stage screening protocol, we identified an EMCCD chip exhibiting high resolution and low noise. The electron-multiplying gain (EM Gain) of the EMCCD was analyzed to determine its impact on signal amplification and noise characteristics, identifying the optimal operational range. Additionally, noise properties such as readout noise were investigated. Experimental results demonstrate that the optimized detector meets CPI-C's initial application requirements, achieving high resolution and low noise. This study provides theoretical and experimental foundations for the use of EMCCD-based WFS in adaptive optics and astronomical observations, ensuring their reliability for advanced space-based imaging applications.
配备电子倍增电荷耦合器件（EMCCD）探测器的波前传感器（WFS）是中国空间站望远镜（CSST）上的冷行星成像日冕仪（CPI-C）的关键组件。对WFS的EMCCD探测器进行精确校准对于满足高对比度系外行星成像的严格要求至关重要。本研究全面表征了探测器的关键性能参数，以确保其适用于天文观测。通过多阶段筛选方案，我们确定了一个具有高分辨率和低噪声的EMCCD芯片。分析了EMCCD的电子倍增增益（EM增益），以确定其对信号放大和噪声特性的影响，确定了最佳工作范围。此外，还研究了读出噪声等噪声特性。实验结果表明，优化后的探测器满足CPI-C的初始应用要求，实现了高分辨率和低噪声。本研究为基于EMCCD的WFS在自适应光学和天文观测中的应用提供了理论和实验基础，确保了它们在先进天基成像应用中的可靠性。
