Scientific Reports (Aug 2017)

Two-color heterodyne laser interferometry for long-distance stage measurement with correction of uncertainties in measured optical distances

  • Zhaowu Liu,
  • Wenhao Li,
  • Bayanheshig,
  • Xiaotian Li,
  • Shan Jiang,
  • Ying Song,
  • Qiang Lv

DOI
https://doi.org/10.1038/s41598-017-07741-4
Journal volume & issue
Vol. 7, no. 1
pp. 1 – 10

Abstract

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Abstract We designed a new system that eliminates deviations by correcting uncertainty in optical distance measurements in the laser two-color heterodyne interferometer. In simulations, eliminating the uncertainty from the atmosphere, the deviation in the uncertainty of the optical distance was 50 times greater with the two-color method than with the one-color method. Adding a correction arm reduces the deviation caused by the uncertainties in measured optical distances. The uncertainty in the measured path length is reduced to 20 nm over a path length of 1500 mm, giving a relative uncertainty of 1.34 × 10 −8.