The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 13, 2022
Filed:
Nov. 16, 2018
Tsinghua University, Beijing, CN;
Yu Zhu, Beijing, CN;
Ming Zhang, Beijing, CN;
Leijie Wang, Beijing, CN;
Weinan Ye, Beijing, CN;
Fuzhong Yang, Beijing, CN;
Yizhou Xia, Beijing, CN;
Xin Li, Beijing, CN;
TSINGHUA UNIVERSITY, Beijing, CN;
Abstract
A five-degree-of-freedom heterodyne grating interferometry system, comprising a single frequency laser device () and an acousto-optic modulator (); the single frequency laser device () emits a single frequency laser, and the single frequency laser is coupled by optical fiber and, after being split, enters the acousto-optic modulator () to obtain two linearly polarized lights of different frequencies, one being a reference light, and one being a measurement light; an interferometer lens group () and a measurement grating (), used for forming the reference light and the measurement light into a measurement interference signal and a compensation interference signal; and multiple optical fiber bundles (), respectively receiving the measurement interference signal and the compensation interference signal, each optical fiber bundle () having multiple multimode optical fibers respectively receiving signals at different positions on the same plane. The present measurement system has the advantages of high measurement precision, a large measurement range, not being sensitive to temperature drift, and small overall size, and can be used as a photoetching machine ultra-precision workpiece table position measurement system.