四象限探测器光斑定位精度影响因素研究

Research on factors affecting spot positioning accuracy of four-quadrant detector

基于四象限探测器的光斑位置检测原理,建立了不同光斑半径、能量分布和探测器死区等影响因素下四象限探测器输出偏置电压与光斑位置的表征关系.数值仿真结果表明:通过选择合适的光斑半径大小、探测器的测量区域、选择死区较小的探测器等,可有效提高探测器的定位精度.基于仿真分析,搭建了测试实验和利用均匀光斑、探测器存在死区情况下的表征方程对测量结果进行数值计算.实验结果表明:与标准值比较,在该表征方法下,在300μm范围内,四象限探测器光斑中心定位精度为0.35μm,均方根为0.18μm.

Based on the spot position detection principle of four-quadrant detector,the characterization of relationship between the output offset voltage of the four-quadrant detector and the position of the laser spot was established under different spot radius,energy distribution and detector dead zone.Numerical simulation results show that the spot positioning accuracy can be effectively improved by selecting appropriate spot radius,measurement area and narrow dead zone of the detector.Based on the simulation analysis,the experiment was carried out,and the results were calculated by using the characterization equation under uniform spot and detector dead zone.Experiment results show that compared with the standard value,under this characterization method,the spot center positioning accuracy of the four-quadrant detector is 0.35μm,and the root mean square is 0.18μm within a range of 300μm.