基于迈克尔逊干涉原理和激光自准直原理，采用共光路布局，研制了能对运动工作台同时进行一维位移和二维角度测量的三自由度激光测量系统。在位移测量中，采用光程差放大技术，并结合偏振干涉技术和信号差分处理，得到高质量的位移输出信号和高分辨力的位移测量结果。在角度测量中，运动工作台的偏摆和俯仰运动会引起固定在工作台上的反射镜位置变化。入射光被反射镜反射，并被四象限探测器探测，根据四象限探测器上的光斑位置变化，获得偏摆角和俯仰角的变化值。对研制的系统进行稳定性和分辨力测试，同时与英国雷尼绍XL-80激光干涉仪进行比对实验。实验结果表明：测量系统的位移分辨力为0.8 nm，角度分辨力为0.2″；在50 mm的测量范围内，与雷尼绍XL-80激光干涉仪测量值相比，系统的位移最大偏差小于100 nm，偏摆角最大偏差为0.5″，俯仰角最大偏差为0.4″。

Common optical path arrangement was adopted to design a three-degree-of-freedom laser meas-urement system for measuring 1D displacement and 2D angles of a moving stage simultaneously on the basis of the principles of Michelson interference and laser auto-collimation. In the displacement measurement, the fine resolution of displacement measurement was achieved by using optical path difference doubling technique. Combined with polarization interference technology and signal differential processing, high-quality displacement output signal was obtained. In the angle measurement, changes in yaw and pitch of a moving stage caused the position change of the mirror which was mounted on the stage. The incident beam was reflected by the mirror and detected by a four-quadrant detector. According to the position change of the spot, yaw and pitch angles were obtained. The stability, resolution tests and the comparison experiments with the British Renishaw XL-80 laser interferometer were done. Experimental results show that the system has the resolution of 0.8 nm for displace-ment measurement and 0.2″ for angle measurement. Compared with the results of Renishaw XL-80 laser inter-ferometer, the maximum deviation of displacement is less than 100 nm within the measurement range of 50 mm. The maximum deviations of yaw and pitch are 0.5″ and 0.4″.