Surface defect measuring apparatus and method by microscopic scattering polarization imaging

US11175220B2 · kind B2 · utility

Assignee

• Shanghai Institute of Optics And Fine Mechanics, Chinese Academy of Sciences · CN

Inventors

• Jianda Shao · Shanghai, CN
• Shijie Liu · Shanghai, CN
• Kaizao Ni · Shanghai, CN
• Shenghao Wang · Shanghai, CN
• You Zhou · Nanhu, CN
• Weiwei WANG · Beijing, CN
• Tianzhu Xu · Shanghai, CN
• Qi Lu · Zhejiang, CN

Key dates

• Filing date: Sep 29, 2020
• Grant date: Nov 16, 2021
• Expiry date: Sep 29, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B5/3025
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A surface defect measuring apparatus and method by microscopic scattering polarization imaging is provided. The apparatus mainly comprises a laser, a first converging lens, a rotary diffuser, a second converging lens, a diaphragm, a third converging lens, a pinhole, a fourth converging lens, a polarizer, a half-wave plate, a polarizing beam splitter, an X-Y translation stage, a sample, a microscope lens, a quarter-wave plate, a micro-polarizer array, a camera and a computer. The micro-polarizer array is adopted to realize real-time microscopic scattering polarization imaging of the surface defects; a polarization-degree image is calculated to improve the sensitivity for detecting the surface defects of the ultra-smooth element, and the effective detection of the surface defects of a high-reflective coating element is also realized, and the requirement for rapid detection of the surface defects of a meter-scale large-aperture ultra-smooth element can be met.