摘要
在构建四象限光电探测器的测量/对准系统数学模型的基础上,提出了一种搜寻算法,以优化系统,使得对准模型具有线性化的输入输出关系,且具有非常高的选择性。系统仿真结果表明,在四象限光电探测器光电转换系数为常数情况下,所提出的模型优化方法正确可行。掩模板位置偏移量与光电探测器的输出具有线性关系,不论是在横向方向还是纵向方向,而且消除了x、y两个方向偏移量的交叉敏感,这使得消除四象限光电探测器安装位置偏差带来的影响成为可能,提高了探测器的应用效率和测量/对准的准确度。模型的实测结果表明,经优化后的系统微位移检测误差与对准误差均小于2μm。
On the basis of the mathematic model of micro-displacement measurement/alignment system with fourquadrant photo-detector, a searching algorithm is presented to optimize the system, linearize the input-output relation and improve the selectivity. System simulation was carried out. Simulation results show that when transformation co- efficient of photo-detector is constant, the proposed optimization method is correct. The input-output characteristic is linear without referencing to the direction of the offset. And the cross-sensitivity between two offsets in x direction and y direction is reduced, which makes it possible to reduce the effect of assembling position of photo-detector on alignment and measurement results. And both the application efficiency and measurement/alignment accuracy are also improved. Practical measurement results show that both micro-displacement measurement and alignment errors are less than 2 μm after the system is optimized.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2008年第7期1359-1364,共6页
Chinese Journal of Scientific Instrument
基金
国家863重大项目(200XAA4C3000)资助
关键词
四象限光电探测器
对准
线性化设计
优化
four-quadrant photo-detector
alignment
linearization design
optimization
