Beam splitter/combiner for optical metrology tool
US7251036B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 2006 |
| Grant date | Jul 31, 2007 |
| Priority date | — |
| Expiry date | Jan 19, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A combiner for optical beams includes a substrate overlaid by a multi-layer dielectric film stack. The substrate is a clear material and the dielectric film stack is a series of alternating layer of high and low refractive index. This gives the combiner relatively high reflectivity across UV wavelengths and relatively high transmissivity in the visible and longer wavelengths and allows visible light to pass through the combiner while UV light is reflected. At the same time dielectric film stack has minimal absorption and scatter. This means that the intensity of visible light maintains at least 90% of its intensity as it passes through combiner and UV light retains at least 90% of its intensity as it is reflected by combiner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.