综述了现有的3类激光光束质量评价方法, 即近场质量、远场质量和传输质量。主要的评价参数包括近场调制度和对比度、聚焦光斑尺寸、远场发散角、衍射极限倍数β因子、斯特列尔比、环围能量比以及M2因子等。讨论了它们各自的适用范围、优点和局限性。提出了采用M2因子矩阵以表述光束的像散特性, 给出了M2因子的不变量。

Three types of evaluation on laser beam quality such as near-field quality, far-field quality, and propagation quality are summarized. The parameters include modulation ratio and contrast ratio of near-field, focused spot size, far-field divergence angle, times diffraction limited factor β, Strehl rate, energy circle rate, M2 factor, etc. The application range, strong point and shortcoming of them especially used in evaluating beam quality of high power laser beam are discussed. Furthermore, a matrix of M2 factor for comprehensive evaluating astigmatic beam has been proposed, and the invariant value is given.