US 11,703,361 B2
Five-degree-of-freedom heterodyne grating interferometry system
Ming Zhang, Beijing (CN); Yu Zhu, Beijing (CN); Fuzhong Yang, Beijing (CN); Leijie Wang, Beijing (CN); Rong Cheng, Beijing (CN); Xin Li, Beijing (CN); Weinan Ye, Beijing (CN); and Jinchun Hu, Beijing (CN)
Assigned to BEIJING U-PRECISION TECH CO., LTD., Beijing (CN); and TSINGHUA UNIVERSITY, Beijing (CN)
Appl. No. 17/257,173
Filed by TSINGHUA UNIVERSITY, Beijing (CN); and BEIJING U-PRECISION TECH CO., LTD., Beijing (CN)
PCT Filed Jun. 26, 2019, PCT No. PCT/CN2019/092921
§ 371(c)(1), (2) Date Dec. 30, 2020,
PCT Pub. No. WO2020/007217, PCT Pub. Date Jan. 9, 2020.
Claims priority of application No. 201810708633.6 (CN), filed on Jul. 2, 2018.
Prior Publication US 2021/0262834 A1, Aug. 26, 2021
Int. Cl. G01D 5/353 (2006.01); G01D 5/34 (2006.01)
CPC G01D 5/3537 (2013.01) [G01D 5/344 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A five-degree-of-freedom heterodyne grating interferometry system, comprising:
a single-frequency laser for emitting a single-frequency laser light, the single-frequency laser light is split into a beam of reference light and a beam of measurement light;
an interferometer lens set and a measurement grating for converting the reference light and the measurement light into a reference interference signal and a measurement interference signal; and
multiple optical fiber bundles receiving the measurement interference signal and the reference interference signal respectively, wherein each of the optical fiber bundles has multiple multimode optical fibers receiving interference signals at different positions on a same plane respectively;
wherein the reference interference signal comprises one path of the reference interference signal, the measurement interference signal comprises two paths of the measurement interference signals, the two paths of measurement interference signals and the one path of the reference interference signal are received via the optical fiber bundles respectively, and
wherein each of the optical fiber bundles has four multimode optical fibers for receiving interference signals at different positions on the same plane respectively, each of the optical fiber bundles outputs four optical signals, thus a total of the optical fiber bundles outputs twelve paths of optical signals.