Related Experiment Video
Updated: Mar 7, 2026

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry
Published on: August 12, 2013
Iterative compensation of nonlinear error of heterodyne interferometer
Abstract:
In order to compensate the nonlinear error of a heterodyne interferometer caused by both frequency mixing and phase demodulating electronics in real time, a novel iterative algorithm with a digital lock-in phase demodulator is proposed in this paper. By using iterative translating and scaling transforms, the phase diagram of the two output signals from phase demodulator is corrected from an ellipse with center offset to a circle at origin. As a result, the correct phase can be obtained and the nonlinear error is compensated. The nonlinear error in heterodyne interferometer is analyzed, the digital lock-in phase demodulator is designed and the iterative compensation algorithm is presented. Simulation and displacement measurement experiments were performed to verify the effectiveness of the proposed method. The experimental results demonstrated that proposed method is able to reduce the nonlinear error obviously and realize nanometer displacement measurement.
More Related Videos
Related Concept Videos
Linear Approximation in Frequency Domain
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
Reconstruction of Signal using Interpolation
Interference: Path Lengths
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Propagation of Uncertainty from Systematic Error
NMR Spectrometers: Resolution and Error Correction
Second Order systems II

