激光合束是实现高功率半导体激光输出的主要途径，常规激光合束提高功率时合束激光的光束质量变差。外腔反馈光谱合束技术利用半导体激光振荡与外部光学系统相结合的方式合束，在提高激光功率的同时，合束激光的光束质量即为激光单元的光束质量。研制出一种基于透射光栅的3个970 nm半导体激光线阵的外腔反馈光谱合束光源，实现连续激光功率为140.6 W、光束质量为4.367 mm·mrad的激光输出，谱宽为36.60 nm，56个波长峰值与激光单元一一对应，为获得高光束质量的高功率半导体激光光源提供了可行的方案。

Laser combining is the main way to develop the high power diode laser source. Traditional beam combining is used to increase the power but leads to a poor beam quality. Spectral beam combining with external cavity feedback improves the characteristics of the power and the beam quality by the way of combining diode laser oscillation with external optical system. By spectral beam combining with external cavity feedback based on a transmission grating, a diode laser source is developed with a continuous wave power of 140.6 W, a beam quality of 4.367 mm·mrad and a spectrum width of 36.60 nm. The whole spectrum is composed of 56 independent wavelength peaks, each one of which is only corresponding to one of the combining laser units, respectively. A feasible solution to obtain a good beam quality for high power diode laser source is demonstrated.