研究了大功率底发射垂直腔面发射激光器（VCSEL）单管器件光束质量，分析了电流、出光孔径、衬底厚度等因素对M2因子、远场发散角、近场及远场光强分布等的影响。使用有限元的方法对不同电极及不同氧化孔径时有源区中电流密度的分布进行了计算，为了获得高功率、高光束质量的VCSEL器件，选择氧化孔径为650 μm以及P面电极直径为580 μm，在对电流进行有效限制的同时实现了有源区中电流密度的均匀分布，从而抑制远场光斑中边模的产生，改善了光束质量。

To research the beam quality of high power vertical cavity surface emitting lasers (VCSELs) singledevices,the impact of the factors such as the current, the aperture, the substrate thickness on the M2 factor, the far field divergence angle, near field and far field intensity distributionsis analyzed. It'sconcluded that, the current density of active area tends to be uniform with the increasing current until the current gets crowded, which inducesall partsemitting and has a circular symmetric beam distribution.The beam quality factor will be smaller with the improved beam quality. On the other hand, with the increasing aperture size of the active region, the lasing intensitydistribution becomes more uneven. While, beam quality will be worse with the increasing aperture size.For the effect of substrate thickness on the beam quality, all the factorsare considered, the optimum substrate thickness is about 100 μm. In order to obtain high power and high beam quality for the VCSELs single device, the oxidation diameter of 650 μm and P side electrode diameter of 580 μm are chosen, which can realize the uniform distribution of current density in the active region and the effective limits on current. This study provides a basis for looking for an effective method to improve the beam quality.