激光光束质量评价是激光光学中的一个经典问题。目前国内外研究人员已经提出多种光束质量评价因子并加以利用，但是对于激光光束质量一直没有统一的评价标准和规范的测量方法。特别是近年来激光相干合成技术得到了迅猛发展，合成后光束质量的评价也缺乏统一的评价方案。本文对已有的各种光束质量因子进行简单评述，并引入光束传输因子(BPF)作为高能激光光束质量通用评价标准。详细介绍了BPF的物理本质与测量方法，并通过模拟计算对其用于评价单束激光和相干合成光束的普适性进行分析。结果表明，BPF具有物理概念明晰、测量方便、通用性强等优势，适合于评价高能激光光束质量。

Laser beam quality evaluating is a classical issue in laser optics field. Several beam quality factors have been proposed and utilized. Nevertheless, there have been no standard methods for characterizing and diagnosing laser beam quality. In addition, with the development of coherent beam combining technique, there is no uniform beam quality factor to evaluate the coherently combined beam. In the present paper, several beam quality factors that already exist are summarized and discussed briefly, then beam propagation factor (BPF) as a universal standard for evaluating high energy beam quality is introduced and studied in detail. The physical principle and the measuring technique in practical engineering are briefly introduced, and the universal characters for evaluating single laser beam and coherent combined beam are analyzed. Numerical calculation results show that BPF is fit for evaluating high energy beam quality due to its advantages in perspicuous principle, handy-for-measuring and all-purpose in application fields.