Method for measuring the diameter of filament diffraction fringes by calculating the frequency domain
US12196540B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 2022 |
| Grant date | Jan 14, 2025 |
| Priority date | — |
| Expiry date | Jan 10, 2043 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30108
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for measuring the diameter of filament diffraction fringes by frequency domain calculation comprising: building a set of diffraction optical path measurement system and capturing diffraction fringe images; determining the starting point of the imaging range; Simulating the electromagnetic field propagation process in Fraunhofer diffraction, and determining the optimal fringe range considering the noise caused by the difference in CCD sensitivity; Finally calculating the filament diameter by Fourier transform for different lengths of fringe. The final value of the calculated filament diameter is obtained by fitting an envelope to the variation of the diameter. The invention is simple in calculation and has little dependence on the experimental device, which means the superiority of using the frequency domain for parameter measurement, and the measurement accuracy is in the sub-nanometer level. In addition, the invention proves the feasibility of extracting the fringe period information in the frequency domain.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.