A Heterodyne Interferometer with Separated Beam Paths for High-Precision Displacement and Angular Measurements

Abstract As standard concepts for precision positioning within a machine reach their limits with increasing measurement volumes, inverse are promising approach addressing this problem. The principle entails other limitations, as high-precision of sensor head large volume, three four-beam interferometers required in order to measure all necessary translations and rotations the reconstruct topography reference system consisting fixed mirrors x -, y z -directions. We present passive heterodyne laser interferometer consequently separated beam paths individual frequencies. path design is illustrated described, well signal-processing evaluation algorithm, which implemented using System-On-a-Chip an integrated FPGA, CPU, A/D converters. A streamlined bench-top optical assembly was set up measurements were carried out investigate remaining non-linearities. Additionally, commercial homodyne executed.