为了提高四象限探测器(QD)光斑位置检测性能，研究了在高斯光斑模型下影响QD位置检测精度的主要因素。分析了四象限探测器位置检测的基本原理，随后根据误差理论推导出高斯光斑模型下位置检测精度与光斑半径、质心位置和系统信噪比关系的数学模型，通过数值仿真和实验分析验证了该数学模型的有效性，并深入分析了各因素对位置检测精度影响的趋势及大小。研究结果表明，对于四象限探测器高斯光斑位置检测系统，在保证检测范围的条件下，采用较小半径的光斑、选取靠近光敏面中心的工作区域和提高系统信噪比可以提高位置检测精度。当系统信噪比为57.48 dB时，采用束腰半径为0.6 mm 的高斯光斑，QD 中心点位置检测精度可达0.514 μm。

In order to improve the spot position detection performance of four-quadrant detector (QD), the main factors affecting QD position detection accuracy in the Gaussian spot model are studied. The basic principle of QD position detection is analyzed. Then on the basis of error theory, the mathematical model of the relationship between position detection accuracy and spot radius, centroid position, signal to noise ratio (SNR) is obtained when a laser spot of Gaussian energy profile illuminates QD. The validity of mathematical model is verified by numerical simulations and experimental analysis. The trends and degree of the factors impact on the position detection accuracy are further discussed. The results show that adoption of smaller spot radius, closer to the center of photosensitive area, and higher SNR, can effectively improve the accuracy of spot detection when the detection range of QD system is fixed. When system′s SNR is 57.48 dB and spot radius is 0.6 mm, the center position detection accuracy of QD can be up to 0.514 μm.