Synthetic model of nonlinearity errors in laser heterodyne interferometry

Abstract

The development of laser heterodyne interferometry raises the requirements of measurement resolution and accuracy. However, periodic nonlinearity errors mainly suppress the accuracy of laser heterodyne interferometry. Based on the generation mechanism of nonlinearity errors, the sources of nonlinearity errors in laser heterodyne interferometry are first analyzed in this paper. Then, a synthetic model is established to analyze the influences of various nonlinearity error sources on the first- and second-harmonic nonlinearity errors. The first-harmonic nonlinearity errors can be reduced and suppressed by adjusting the orientation error of optical elements in a heterodyne interferometer. Furthermore, the azimuthal misalignment of the polarization beam splitter (PBS) is the main source of the second-harmonic nonlinearity errors. Therefore, when in heterodyne interferometer, the azimuthal misalignment of the PBS should be avoided if possible. This study provides theoretical basis for reducing and compensating nonlinearity errors in a laser heterodyne interferometer.

A Picometre-Level Resolution Test Method without Nonlinearity for Heterodyne Interferometer Measurement Electronics

“…However, in the proposed testing device, since only the linear modulation region is used, harmonics distortion is very low according to Equation (20). Moreover, in contrast to periodic nonlinearity in the heterodyne interferometer [35,36], the harmonic frequencies in the testing device are far away from the center frequency, and the harmonics in Equation ( 19) are basically filtered out by the analog and digital filters in the measurement electronics. Therefore, it is not necessary to worry about the modulation nonlinearity of the AOM in the proposed resolution test method.…”

Improved laser measurement using advanced techniques: A review

“…55 Furthermore, in 2018, Hongfang Chen et al established a synthetic model to analyze the impact of various nonlinearity error sources, to provide theoretical basis for further compensating nonlinearity errors. 56 In 2020, Hongxing Yang et al designed a novel laser source with high stability, which improved the measurement speed and the resolution simultaneously. 57 Almost at the same time, Hsieh Hung-Lin et al proposed a heterodyne speckle interferometry system which realized a two-dimensional displacement measurement with a resolution of approximately 1.5 nm.…”

“…In 2017, a novel dual‐homodyne interferometer measurement method further suppressed the periodic nonlinearity error and realized large displacement measurement with a nanometer accuracy 55 . Furthermore, in 2018, Hongfang Chen et al established a synthetic model to analyze the impact of various nonlinearity error sources, to provide theoretical basis for further compensating nonlinearity errors 56 . In 2020, Hongxing Yang et al designed a novel laser source with high stability, which improved the measurement speed and the resolution simultaneously 57 .…”

Calibration of Displacement Laser Interferometer Systems for Industrial Metrology

“…It is known that laser interferometer systems exhibit linearity errors due to the interpolation between fringes, the δ in Equation (1). These have been intensively studied and modeled in literature [27,28,29]. In these studies on periodic linearity, usually a third-order polynomial or several harmonics of a Fourier transform are used to describe the deviations.…”