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:
Feb. 22, 2022
Filed:
Sep. 04, 2019
Zhejiang Sci-tech University, Zhejiang, CN;
Liping Yan, Zhejiang, CN;
Benyong Chen, Zhejiang, CN;
Yingtian Lou, Zhejiang, CN;
Jiandong Xie, Zhejiang, CN;
ZHEJIANG SCI-TECH UNIVERSITY, Zhejiang, CN;
Abstract
The disclosure discloses a differential sinusoidal phase modulation laser interferometric nanometer displacement measuring apparatus and method. The beam output from the single-frequency laser is converted into a 45° linearly polarized beam after passing through the polarizer, then projected onto two sets of sinusoidal phase modulation interferometers consisting of the beam splitter, the electro-optic phase modulator, the half wave plate, three pyramid prisms, two polarization beam splitters, thereby forming measurement and reference interference signals which are received by two photodetectors. A high-frequency sinusoidal voltage signal is applied to the electro-optic phase modulator placed in the common reference arm of the two interferometers, thereby modulating the interference signal into a high-frequency AC signal. By detecting the difference between the phase change amounts of the two interference signals when the measured object moves, the measured displacement can be obtained.