在波长光束组合基础上，用一个光栅和一个准直透镜代替传输透镜，可以有效地减小单个发光单元光束质量的退化，明显地克服相邻发光单元的反馈串扰，实现了较窄线宽的光谱组束输出。采用标准的半导体激光阵列，连续输出激光功率44.8 W，电光转换效率最高38.9%，光谱线宽为4.1 nm。光束慢轴方向光束质量因子为11.7，快轴方向光束质量因子为1.37，快慢轴两个方向都接近单个发光单元光束质量。

A grating and a collimating lens are used to replace the transformer lens in the traditional spectral beam combining structure. As a result, the degradation of the beam quality and the cross-talk are prevented. A spectral beam combining with narrow line-width is achieved. A standard semiconductor laser array is employed in this experiment. An output power of 44.8 W and an electro-optic conversion efficiency of 38.9% are achieved. The spectral line-width is 4.1 nm. A beam quality factor of 1.37×11.7 in fast and slow axis directions are obtained. The beam quality of the output is close to that of a single emitter of the array in both directions.