制作了一个基于受激布里渊散射效应的全光纤结构窄线宽双波长激光器，其波长间隔为0.06 nm，输出功率为4.5 W，光光转换效率为50%。对它的光谱特性、功率输出特性和相干性与单波长窄线宽光纤激光器进行对比研究表明，该双波长光纤激光器具有和单波长光纤激光器类似的功率输出特性，窄线宽双波长光纤激光器同样具有较好的相干性。在最大功率输出时，远场干涉条纹对比度达到80%。该窄线宽双波长光纤激光器可用于光束相干合成。

A 4.5 W all-fiber narrow-linewidth two-tone laser based on stimulated Brillouin scattering is established. The wavelength separation of two-tone laser is 0.06 nm. The output power is 4.5 W and the optical conversion efficiency is 50%. Spectral properties, output power properties and coherence of the laser are compared with single-tone fiber laser experimently. Experiment results indicate that the narrow-linewidth two-tone fiber laser has the similar output power properties with the single-tone fiber laser. The visibility of the far-field interference pattern reaches 80%, when the two-tone fiber laser is at the max output power. The narrow-linewidth two-tone fiber laser can be used for coherent beam combination.