Method and apparatus for wafer-level measurement of volume holographic gratings
US7359046B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2006 |
| Grant date | Apr 15, 2008 |
| Priority date | — |
| Expiry date | Jun 27, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2001/2247
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention describes a system for the measurement of volume holograms on a wafer scale that permits high-resolution and high throughput measurement of grating parameters. The invention uses a collimated beam of a fixed wavelength light source that is transmitted through the wafer to be tested. The transmitted beam is imaged with a lens onto a sensor. The sensor is used to measure the beam power under a variety of conditions, including without a wafer in place, so that the various measurements can be used to determine grating characteristics. The measurement data produced includes values for grating spacing, tilt angle, and diffraction efficiency with a high spatial resolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.