针对现有激光自混合干涉(SMI)角度测量方法无法判别角度旋转方向的缺陷,提出一种基于SMI和表面等离子体共振(SPR)的、能判别旋转方向的角度测量方法。通过判断出射激光束的平均光强变化,确定被测物体旋转的方向;通过预先标定好的激光SMI输出光强和旋转角度间的对应关系,实现对被测物体旋转角度的测量。搭建了旋转平台微小旋转角度的测量系统,测量结果表明,本方法除能高精度测量旋转角度外,还能有效判别角度的旋转方向。 Aiming at the defect that the angle measurement method can not distinguish the direction of rotation from the existing methods of SMI angle measurement, an angle measurement method based on SMI and surface plasmon resonance (SPR) is proposed to determine the rotation direction. By determining the average light intensity of the outgoing laser beam, the rotation direction of the measured object is determined. The corresponding relationship between the output light intensity and the rotation angle of the laser SMI is calibrated to measure the rotation angle of the measured object. The measurement system of the rotation angle of the rotating platform is set up. The measurement results show that the method can not only measure the rotation angle accurately, but also effectively distinguish the rotation direction of the angle.