Transportable distance measurement system based on superheterodyne interferometry using two phase-locked frequency-doubled Nd:YAG lasers

摘要

We describe a transportable distance measurement system based on synthetic wavelength interferometry. Two frequency-doubled Nd:yttrium aluminum garnet lasers at 532 nm are used to generate a synthetic wavelength of ∼ 2.5 cm. A nonpolarizing interferometric system has been set up to eliminate polarization cross-talk issue. A superheterodyne detection was performed to measure the synthetic phase and to determine absolute distances. The capability to achieve fringe interpolation of 2π/5600 has been demonstrated and an agreement in distance measurement at the 4 μm level has been achieved, compared to an optical interferometric 3 m long displacement bench. © 2010 American Institute of Physics Article Outline INTRODUCTION PRINCIPLE EXPERIMENTAL SETUP Synthetic wavelength heterodyne interferometer Phase detection of the superheterodyne signal Determination of the fringe order EVALUATION OF THE SYSTEM AND RESULTS Stability Linearity Test of accuracy CONCLUSIONS AND DISCUSSION