Ultraviolet ray transmissive filter and method for producing same
US11762139B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 2021 |
| Grant date | Sep 19, 2023 |
| Priority date | — |
| Expiry date | Mar 31, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/285
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Provide is an ultraviolet ray transmissive filter in which a crystal structure of a hafnium oxide layer is controlled to improve the light resistance of an optical interference film, and which can suppress reduction of the transmissivity in a transmission band even under long-term irradiation with ultraviolet rays. The optical interference film includes the hafnium oxide layer, and in the crystal structure of the hafnium oxide layer, spectral peak intensities from X-ray diffraction which are derived from the orthorhombic crystal structure and a tetragonal crystal structure are lower than a spectral peak intensity from X-ray diffraction which is derived from the monoclinic crystal structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.