Research On The Micro-displacement Measurement System Based On Laser Interferometer

Laser interferometer measurement is a comprehensive technology to achieve precision/ultra-precision measurement. In term of the laser interferometer, when collecting the nanoscale/sub-nanoscale data of displacement, the accuracy of data will be immensely affected by the air temperature, air pressure and humidity of test condition. In order to increase the accuracy of single frequency laser interferometer, the paper researched the compensation algorithm which can affect the refractive index of light, meanwhile, the design tends to increase the data measurement accuracy from the nanoscale level to sub-nanoscale one.As the algorithm for Edlen refractive index of air cannot solve the current atmospheric environment, this paper will add the improved version of the algorithm to micrometric displacement measurement software installed in single-frequency laser interferometer, and finally get the measurement result compensated. What's more, using the C# programming can improve the accuracy to level of sub-nanoscale.In order to verify the practical performance of the enhanced software, the paper sets up the experimental platform, measures the displacement of the moving object using XL-80 single-frequency laser interferometer; the moving object is controlled by C.300 micro-displacement controller. Result shows that the accuracy of measurement data is in sub-nanoscale range.In this paper, micro displacement measurement software improves the accuracy of collecting data in the micro-displacement measurement.