靶面焦斑合束数值模拟研究可为准分子激光角多路系统建设提供重要参考。首先介绍了靶面激光焦斑合束的计算方法，进而基于单束激光焦斑形态和光束指向稳定性开展了18束准分子激光靶面合束计算，给出了合束焦斑的形态及评价参数。最后，基于准等熵压缩实验的要求，研究了不同系统成像质量对激光指向稳定性的要求。研究表明：多束激光焦斑合束有利于提高焦斑均匀性；高系统成像质量需要较高的光束指向稳定性来保证合束焦斑的均匀性，否则高系统成像质量的优势得不到体现；系统成像质量较差时，光束指向稳定性处于一定范围内即可，更高的激光指向稳定性对焦斑的均匀性改善不显著。

Numerical study on focal spot overlapping can provide important supports for the construction of an excimer laser angular multiplexing system. The simulation methods of focal spots overlapping are introduced first. And then simulations of 18 laser beams overlapping are performed based on single laser beam focal spot profiles and laser pointing stability. Profiles and parameters of overlapped laser focal spot on target surface are given. Finally, the relations between imaging quality and laser pointing stability are studied under the requirements of isentropic compression experiments. Many conclusions are drawn from the study. The uniformity of focal spot can be raised by overlapping. What′s more, better beam pointing stability is needed to keep the uniformity when the imaging quality is excellent. Otherwise, the outstanding imaging quality is wasteful. The beam pointing stability can just be within a certain range when imaging quality is common, for the uniformity cannot be improved much by better laser pointing stability.