TWO-DEGREE-OF-FREEDOM HETERODYNE GRATING INTERFEROMETRY MEASUREMENT SYSTEM

摘要

Disclosed is a two-degree-of-freedom heterodyne grating interferometry measurement system, comprising: a single-frequency laser device (1) for emitting a single-frequency laser, wherein the single-frequency laser can be split into a beam of reference light and a beam of measurement light; an interferometer mirror group (3) and a measurement grating (4) for forming a reference interference signal and a measurement interference signal from the reference light and the measurement light; and a receiving optical fiber (5) for receiving the reference interference signal and the measurement interference signal, wherein a core diameter of the receiving optical fiber (5) is less than the width of an interference fringe of the reference interference signal and the measurement interference signal, so that the receiving optical fiber (5) receives a part of the reference interference signal and the measurement interference signal. The measurement system has the advantages of insensitivity to a grating rotation angle error, a small volume, a light weight, facilitating arrangement, etc., and is particularly suitable for a scenario with a higher requirement for an installation error in industrial application.