在水导激光加工中, 聚焦激光与微细水束的耦合对准效果是实现水导激光稳定加工的关键。为了提高水导激光的耦合对准精度, 提出了一种新的耦合对准方法, 即采用一种双透镜离轴光学系统, 系统中一透镜进行轴向移动从而调节束腰轴向位置, 另一透镜与喷嘴一起进行径向移动从而调节束腰径向位置。该方法可以有效提高对准装置的分辨率, 从而实现高精度的耦合对准。对该方法进行了理论分析, 并根据理论分析进行了实验装置的设计。实验结果表明该方法将耦合对准装置的径向分辨率提高了5倍, 与预期设计相符。应用该方法成功将激光耦合进入直径100 μm的喷嘴中实现水导激光加工, 该方法也是离轴光学系统的一个创新应用。

The laser and water-jet coupling technology is the key to realize water-jet guided laser machining. In order to improve the coupling accuracy, a new method was put forward based on off-axis optical system. The system was mainly composed of two convex lens, one for adjusting the axial position of laser beam waist, another lens for adjusting the radial position. The method can effectively improve the resolution of the coupling device. The theoretical analysis of the method was carried out, and an experimental apparatus was designed according to the analysis. The experimental results show that this method increases the radial resolution of coupling device by 5 times, which is consistent with the design. This method has been applied successfully to couple the laser into the nozzle of 100 μm diameter, and it is also an innovative application of off-axis optical systems.