为了进一步提高激光光束用作直线基准的精度, 建立了基于反射镜平动式光束稳定器以及两点式光束漂移分离法的高精度激光光束准直系统。首先, 对系统中基于反射镜平动的光束稳定器进行研究, 对其光束偏转原理以及影响因素进行分析, 并对两点式光束漂移分离方法进行介绍。然后, 对光束偏转单元的分辨力以及偏转范围、所使用的压电陶瓷非线性和迟滞特性、以及光束偏转单元的频率响应特性进行实验测试。最后, 对该激光准直系统的激光光束准直精度进行测试。实验结果表明: 本文提出的光束偏转单元在120 μrad范围内的光束偏转分辨力可以达到5 nrad, 频率响应特性高于2 kHz; 最终激光准直系统的准直精度在二维方向上分别达到1.9×10-8 rad和2.1×10-8 rad, 相对于现有技术约提高了3倍, 满足激光光束用作高精度直线基准的需求。

To further improve the accuracy of laser-beam linear datum, a high-accuracy laser collimation system based on a high resolution and high frequency response beam stabilizer and a two-point beam drift separation method was established in this study. First, the translation mirror-based beam stabilizer of the system was studied, and its beam deflection principle and influence factor were analyzed in addition with the two-point beam drift separation method. Then, the resolution and deflection ranges of beam stabilizer, the nonlinearity and hysteresis of piezo, and the associated frequency response were tested. Finally, experimental tests were conducted to determine the accuracy of the laser collimation system. Experimental results indicate that a resolution of 5 nrad of the beam stabilizer can be achieved in deflection range of 120 μrad with frequency response higher than 2 kHz. Furthermore, accuracies of 1.9×10-8 rad and 2.1×10-8 rad of the laser-beam collimation system in 2D directions are obtained, which are both 3 times higher than those corresponding to existing technology. The investigated system is, therefore, capable of satisfying the high accuracy requirements of linear datum using laser-beam.