由于超连续谱(SC)光源具有宽谱特性，针对传统方法无法对其光束质量进行全局评价的缺陷，提出SC-M2因子这一参数。使用分步傅里叶法求解广义非线性薛定谔方程，获得超连续谱光源的光谱分布，根据光谱二阶矩方法可得到光谱重心。应用有限元方法获得超连续谱光源的近场空间分布，经自由空间传输之后获得其远场分布。由超连续谱光源的近场、远场分布以及光谱重心，定义SC-M2因子对其光束质量进行全局评价。使用这一方法可对超连续谱光源的光束质量进行全面分析，并且适用于不同超连续谱光源之间的比较。

Due to the wide spectra, the conventional methods can not evaluate the beam quality of the whole supercontinuum (SC). A new factor SC-M2 is introduced. The spectra of supercontinuum is obtained by solving the generalized nonlinear Schrdinger equation by the using of split-step Fourier method. The spectral centroid is calculated based on second-moment method. The near field optical power distribution of the supercontinuum source is obtained by the using of finite element method. After free space propagation, the far field distribution is obtained. Founded on the near field, far field and spectral centroid, the SC-M2 factor is defined to evaluate the beam quality of supercontinuum source as a whole. With this factor, the beam quality of supercontinuum source can be evaluated comprehensively and comparison among different supercontinuum sources can be made.