Holographic grating lithography system and a method for adjusting the self-collimation of the interference optical path thereof
US10838361B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2019 |
| Grant date | Nov 17, 2020 |
| Priority date | — |
| Expiry date | Aug 7, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2223/52
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A Volume Bragg grating (VBG) is placed in the back of a collimating lens, the incident angle between exposure light beam and the Volume Bragg grating is equal to the Bragg angle of the Volume Bragg grating. A photodetector is placed in the −1 grade transmission diffraction light path of the Volume Bragg grating which the exposure light beam is emitted to. The pinhole filter is moved back and forth along an optical axis and the reading of the photodetector is observed in real time. When the reading of the photodetector is maximum, fix the pinhole filter and keep the distance between the first pinhole filter and the first collimating lens a constant. The method for adjusting the self-collimation optical path is provided, using the Volume Bragg grating to detect the parallelism of self-collimation light and substituting for a traditional Moire pattern adjustment method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.