光纤激光谱组束技术是实现大功率、高质量光纤激光输出的有效手段。在传统的外腔谱组束系统中，离轴阵元的效率下降限制了其组束潜力；在基于PTR布拉格光栅的谱组束系统中，随着组束阵元数目的增加，系统复杂程度、体积和重量随之增大，限制了其应用范围。针对当前谱组束系统中存在的诸多问题，采用凹面光栅作为色散元件构建新的谱组束系统。凹面光栅同时具有衍射分光和聚焦的功能，应用于谱组束系统中不仅可以解决离轴阵元效率下降问题，而且降低系统的复杂程度，有利于输出稳定性的提高。

Spectral beam combination of fiber lasers is a valid method for producing laser output with high power and good beam quality. In traditional external cavity-based spectral beam combination of fiber lasers, the combining potential is restricted by the decline of coupling efficiency. And for the systems based on PTR Brag gratings, with the increase of combing beams, the systems complexity, volume and weight improve, which restricts their practical applications. Thus in this paper, a novel spectral beam combination scheme for fiber lasers based on concave gratings is presented. The scheme can solve the problem of coupling efficiency decline, predigest the system and improve the stability of output beam.