Automated defect detection and mapping for optical filters
US9927369B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 3, 2016 |
| Grant date | Mar 27, 2018 |
| Priority date | — |
| Expiry date | Jul 2, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/068
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Devices and methods are disclosed for characterizing point flaws (including pinholes and point defects) of an optical filter. A passband test is performed, including: illuminating the optical filter with passband illumination whose spectral range at least overlaps a passband of the optical filter; acquiring a passband map of the optical filter using a two-dimensional array of photodetectors while illuminating the optical filter with the passband illumination; and identifying point defects of the optical filter as low intensity locations of the passband map. A stopband test is performed, including: illuminating the optical filter with stopband illumination whose spectral range lies entirely outside of the passband of the optical filter; acquiring a stopband map of the optical filter using the two-dimensional array of photodetectors while illuminating the optical filter with the stopband illumination; and identifying pinholes of the optical filter as high intensity locations of the stopband map.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.