Patents by Inventor Zhaowu LIU

Zhaowu LIU has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 12241739
    Abstract: A bidirectional Littrow two-degree-of-freedom grating interference measurement device based on double gratings includes a transmission two-dimensional grating and a reflection two-dimensional grating. A dual-frequency laser emitted by a light source passes through the transmission two-dimensional grating with a specific grating pitch to form four beams in X direction and Y direction, the four beams are incident on the reflection two-dimensional grating at a Littrow angle, and the four beams diffracted by the reflection two-dimensional grating return to the transmission two-dimensional grating in an incidence direction along the same path; different orders of transmission light of the four beams of light in different directions may form stable interference signals carrying displacement information, and the stable interference signals are received by a detector.
    Type: Grant
    Filed: September 25, 2024
    Date of Patent: March 4, 2025
    Assignee: Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences
    Inventors: Wenhao Li, Wenyuan Zhou, Zhaowu Liu, Yujia Sun, Lin Liu
  • Publication number: 20250068123
    Abstract: A method and a device for compensating a surface error of a holographic grating substrate based on scanning and exposure technology relates to a technical field of grating development. The method and the device adopt surface error compensation technology based on phase modulation of interference fringes of a scanning beam interference lithography system. The method and the device solve a poor grating diffraction wavefront quality caused by a surface processing error in a field of holographic grating research and improves full-aperture diffraction wavefront quality of a grating.
    Type: Application
    Filed: August 22, 2024
    Publication date: February 27, 2025
    Inventors: HESHIG BAYAN, SHAN JIANG, YUBO LI, ZHAOWU LIU, WEI WANG, WENHAO LI, SHUO LI, YANXIU JIANG
  • Patent number: 12188794
    Abstract: Disclosed are a grating displacement measurement device and a grating displacement measurement method using a double-layer floating reading head, a medium, and an apparatus. A first measurement grating group is arranged on two first side edges of a substrate working surface, and a second measurement grating group is symmetrically arranged on both sides of a first reference line and close to a light-through member. A reading component is provided between a first measurement grating and a second measurement grating arranged on the same side, and each reading component is used to collect a first position information of the first measurement grating and a second position information of the second measurement grating. In the technical solutions, by using multi-channel position information output by two reading components in combination with a displacement solution algorithm.
    Type: Grant
    Filed: September 20, 2024
    Date of Patent: January 7, 2025
    Assignee: Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences
    Inventors: Wenhao Li, Wenyuan Zhou, Zhaowu Liu, Shan Jiang, Wei Wang, Yujia Sun, Lin Liu, Xu Liang, Siyu Jin
  • Patent number: 12188793
    Abstract: A heterodyne two-dimensional grating measuring device and measuring method thereof includes a light source, a reading head, a photoelectric receiving module, and a processor. The light source is configured to generate two beams of linearly polarized light having characteristics of overlapping, polarization orthogonal, and fixed frequency difference. The reading head is configured to receive the two beams of the linearly polarized light, the two beams of the linearly polarized light are respectively incident on a surface of a moving two-dimensional measuring grating to generate ±1-order diffracted lights of two dimensions, and the ±1-order diffracted lights are respectively incident to the photoelectric receiving module through the reading head.
    Type: Grant
    Filed: March 31, 2022
    Date of Patent: January 7, 2025
    Assignee: CHANGCHUN INSTITUTE OF OPTICS, FINE MECHANICS AND PHYSICS, ACADEMY OF SCIENCES
    Inventors: Wenhao Li, Zhaowu Liu, Hongzhu Yu, Wei Wang, Rigalantu Ji, Xuefeng Yao
  • Patent number: 11860057
    Abstract: A heterodyne one-dimensional grating measuring device and measuring method thereof, including a light source, a reading head, a photoelectric receiving module, and a signal processing system. The light source is configured to generate two linearly polarized lights having characteristics of overlapping, polarization orthogonal, and fixed frequency difference. The reading head is configured to receive two beams of polarized lights and be respectively incident on a surface of a moving measuring grating to generate a +1-order diffracted light and a ?1-order diffracted light. The photoelectric receiving module is configured to receive the +1-order diffracted light and the ?1-order diffracted light to form two paths of beat frequency signals. The signal processing system is configured to perform differential calculation on the two paths of the beat frequency signals to realize a displacement measurement of single diffraction of the measuring grating for four-fold optical subdivision.
    Type: Grant
    Filed: March 31, 2022
    Date of Patent: January 2, 2024
    Assignee: CHANGCHUN INSTITUTE OF OPTICS, FINE MECHANICS AND PHYSICS, CHINESE ACADEMY OF SCIENCES
    Inventors: Wenhao Li, Zhaowu Liu, Wei Wang, Hongzhu Yu, Rigalantu Ji, Xuefeng Yao
  • Publication number: 20220228890
    Abstract: A heterodyne two-dimensional grating measuring device and measuring method thereof includes a light source, a reading head, a photoelectric receiving module, and a signal processing system. The light source is configured to generate two beams of linearly polarized lights having characteristics of overlapping, polarization orthogonal, and fixed frequency difference. The reading head is configured to receive the two beams of the linearly polarized lights, the two beams of the linearly polarized lights are respectively incident on a surface of a moving two-dimensional measuring grating to generate ±1-order diffracted lights of two dimensions, and the ±1-order diffracted lights are respectively incident to the photoelectric receiving module through the reading head.
    Type: Application
    Filed: March 31, 2022
    Publication date: July 21, 2022
    Inventors: WENHAO LI, Zhaowu Liu, Hongzhu Yu, Wei Wang, Rigalantu Ji, Xuefeng Yao
  • Publication number: 20220221372
    Abstract: A heterodyne one-dimensional grating measuring device and measuring method thereof, including a light source, a reading head, a photoelectric receiving module, and a signal processing system. The light source is configured to generate two linearly polarized lights having characteristics of overlapping, polarization orthogonal, and fixed frequency difference. The reading head is configured to receive two beams of polarized lights and be respectively incident on a surface of a moving measuring grating to generate a +1-order diffracted light and a ?1-order diffracted light. The photoelectric receiving module is configured to receive the +1-order diffracted light and the ?1-order diffracted light to form two paths of beat frequency signals. The signal processing system is configured to perform differential calculation on the two paths of the beat frequency signals to realize a displacement measurement of single diffraction of the measuring grating for four-fold optical subdivision.
    Type: Application
    Filed: March 31, 2022
    Publication date: July 14, 2022
    Inventors: WENHAO LI, ZHAOWU LIU, WEI WANG, HONGZHU YU, RIGALANTU JI, XUEFENG YAO
  • Publication number: 20220146249
    Abstract: A grating displacement measuring device based on conical diffraction, including a laser diode configured to emit a measuring beam, a collimating lens, a polarizing beam splitter, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, a fourth reflecting mirror and a phase shift measuring unit. A grating displacement measuring method based on conical diffraction is also provided.
    Type: Application
    Filed: January 24, 2022
    Publication date: May 12, 2022
    Inventors: Wenhao LI, Zhaowu LIU, Wei WANG, Lin LIU, Shan JIANG, Hongzhu YU, Yanxiu JIANG