电子倍增CCD噪声因子模型及测试方法

Noise Factors Model of Electron Multiplying CCD and Test Methods

基于泊松分布模型推导了电子倍增电荷耦合器件的噪声因子,定量描述了电子倍增电荷耦合器件倍增寄存器的输入输出特性以及在信号倍增过程中引入的额外噪声.通过对采集的均匀照明目标的图像信息进行分析处理,消除了读出噪声、固定图案噪声和本底值对测试结果的影响,减小了测试误差,提高了测试准确度,且无需对芯片镀膜,简化了测试工艺.在理论研究基础上,对Andor公司的Luca相机进行了实验测试.结果表明:当增益大于100时,电子倍增电荷耦合器件的噪声因子为1.414,与传统的二项分布模型一致,验证了本文提出的测试方法的可行性和可靠性.

The noise factor of the electron multiplying CCD was derived based on Poisson distribution model whose theoretical limit was √2, the same as binomial model. The input and output characteristics of the electron multiplying register and the additional noise introduced by signal multiplication process were quantitatively described. Considering the defects of coating test, the image information of uniform illuminated was analyzed and processed. The influence of readout noise, fixed pattern noise and background values to test results was eliminated. This method reduced the test error and improved the precision. Meanwhile, the chip was uncoated and test process was simplified. Based on theoretical study, the experiments were carried out to test Andor Luca camera. The results show that when the gain is greater than 100, the electron multiplying CCD noise factor is 1.414, consistent with the theoretical values. This demonstrates that the proposed test is feasible and reliable.