以光束质量(BQ)作为二维激光相干组束系统输出激光光束质量的评价因子，对相干组束系统的光束质量进行了实验研究。利用光反馈环形腔被动相位锁定技术，搭建了二维4路光纤激光相干组束的实验平台，实现了4路光纤激光的相干组束。当选取理想光束口径为近场子光束外切圆直径时，以圆形平顶光束或高斯光束作为理想光束模型，对应不同的远场光斑桶尺寸，分别进行了BQ测量。结果表明，BQ定义中理想光束模型的选择对BQ影响较小，而远场光斑桶尺寸的选取对BQ影响较大。对于不同相干组束系统的BQ评价，需要在明确BQ定义的情况下进行。

Beam quality (BQ) of the coherent beam combination system of lasers in two-dimensional distribution is studied with BQ as the evaluation factor for beam quality of the output laser. By using passive phase locking technology with optical feedback in a ring cavity, the experimental setup of coherent beam combination of four lasers in two dimensions is built, and the combination of four fiber lasers is realized. When the diameter of ideal beam is selected as the circumscribed circle diameter of sub-beams in near-field, circular flat-topped beam or Gaussian beam is taken as the ideal beam model. Corresponding to different bucket sizes of laser spot in far-field, BQs are measured separately. The results show that, the selection of ideal beam model in the definition has little effect on BQ, but the selection of bucket size of laser spot in far-field has greater impact on BQ. The BQs of different coherent beam combination systems should be evaluated with a clear definition of BQ.