高精度滚转角干涉仪

提出了一种基于横向塞曼激光器的新的滚转角测量系统。该系统在已有技术的基础上 ,将测量放大倍率又扩展了 4倍 ,从而大大提高了滚转角的测量精度。系统以横向塞曼激光器出射的正交线偏振光作为测量光 ,首先经 1 /4波片将线偏振光变成微椭圆偏振光 (即进行微椭偏化 ) ,然后测量光通过作为传感器的 1 / 2波片 ,由直角反射镜将光路折回 ,使测量光再次通过作为传感器的 1 / 2波片。由于直角反射镜提供了合理的坐标变换 ,所以使得测量光在两次通过1 / 2波片时 ,偏振方向的改变被叠加了 ,相当于被测量的滚转角放大了 4倍。最后测量光经检偏器合成 ,再用光电探测器接收。由测量光的相位变化可以求出工作台的滚转角变化。在整周期内 ,测量光的相位变化与滚转角成非线性关系 ,但在特定的角度上会出现线性很好的滚转角测量灵敏度倍增区。采用这种方法 ,测量放大倍率可以达到 2 0 0倍 ,能够实现高精度的滚转角测量。使用分辨率为 0 0 0 3°的相位计 ,滚转角的测量分辨率可达到 0 1″。

High precision roll angle interferometer

A new roll angle measurement system using transverse Zeeman laser is presented. High precision roll angle measurement is realized with t his system. The amplification of the angle is increased by four times than the e xist technology. The transverse Zeeman laser gives off orthogonal linear polariz ed light, which is changed to be slightly ellipse polarized light by a quarter w ave p late. Then the beam passes a half wave plate that is employed as sensor and refl ects by a corner cube mirror. The beam passes the half wave plate again. Because the corner mirror gives reasonable transformation of coordinates, the change of polarized direction is accumulated while beam passes the half wave plate twice. Final the measurement signal is detected by photo-diode. Measuring the phase c h ange of the beam signal, value of the roll angle of the sensor is got. Employing the phase detector that has the resolution of 0.003 degree, the system has sens itivity of 0.1 second in roll angle measurement.