基于双色镜的光谱合成技术可突破单个光纤激光器输出功率极限的限制，是获得高功率、高光束质量激光输出的有效技术手段。理论上，初步探究了参与合成的光束位置偏移及倾斜误差对合成光束质量的影响，结果表明光束倾斜误差对合成系统的输出特性影响显著。实验上，开展了两路窄线宽光纤激光器的合成实验，使用双色镜作为合成元件，获得了最大输出功率为2355 W的高光束质量共孔径合成输出，光束质量M²为1.9，合成效率大于99%，实验验证了双色镜在反射和透射情况下具有较高的效率。通过进一步提高单路光纤激光的输出功率或增加合成路数，可以实现更高功率和更好光束质量的共孔径激光输出。

Spectral beam combining technology based on dichromatic mirror can overcome the limitation of the output power limit of one single-mode fiber laser, which is an effective technical means to obtain laser output with high power and perfect beam quality. Theoretically, the influence of the beam position shift and tilt error on the quality of the combined beam was preliminarily explored. The results show that the beam tilt error has a significant influence on the output characteristics of the combining system. In the experiment, the combining experiment of two narrow linewidth fiber lasers was carried out. Using dichromatic mirrors as the combining element, a high beam quality and common-aperture combining with 2355 W combined output power was achieved, the beam quality factor M² was 1.9, and the efficiency was greater than 99%, which proves that the dichromatic mirror has high efficiency for both the reflection and transmission cases. The experiment result shows that it is possible to achieve a common aperture laser output with higher power and better beam quality by further increasing the number and power of the channel.