用多个UR90腔进行正向模耦合的方法来产生多束相干的激光,解决了反向模耦合中存在的失谐问题,可以大大提高系统的可靠性。并利用铜蒸气激光器实现了两台低放大倍率(M=1.21)UR90腔的相干并束输出,对输出光束的远场方向性进行了测量分析。结果表明,和以前单台UR90腔相比,此方法对UR90腔的模控能力和输出光束的光束质量并没有明显影响,是一种简单而有效的耦合方式。

In this paper, a new method of obtaining multi-coherent-beams by UR90 resonators coupled with forward-mode was given, by which a problem was called “detune” existing in method of backward-mode was resolved, and the reliability of system was enhanced obviously. The far-field intensities and divergence angles of combined beam of two copper vapor lasers with UR90 resonators coupled at small magnification (M=1.21) were measured and analyzed experimentally. The results demonstrated that the mode-control ability and far-field intensity distributions of UR90 resonators coupled by forward-mode are still good.