为了研究小角度失调对二维轴对称－折叠组合腔CO₂激光器输出光束的近场分布的影响，在利用矩阵理论确定平凹谐振腔和凹－平－凹谐振腔失调后的光轴的基础上，采用光束并和思想，对输出光束进行了理论分析和模拟。取得的数据表明，小角度失调对4cm以内的近场强度影响不大，光强仍具有高斯状分布；对4cm以外的近场强度影响较大，光强分布轮廓发生相应的变形，且随着失调角度变大而变大。研究结果表明，在4cm以内的近场具有实用价值。

Under the condition of small angle misalignment,the effecton output beam's near-field distribution of CO₂ lasers with two-dimensional axisymmetric-fold combination cavity was ascertained after analyzing and simulating beams combination output based on the axis determination of misaligned plano-concave and concave-plano-concave cavity resonator. The results showed that at small angle misalignment,the effect on near-field within 4cm was un-conspicuous and the light intensity was still at Gaussian distribution,and that out of the 4cm area,the effect became obvious with the misalignment angle. These results showed that the effect on near-field with 4cm was more practically.