System for monitoring intensity during holographic exposure
US4968138A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 8, 1988 |
| Grant date | Nov 6, 1990 |
| Priority date | — |
| Expiry date | Dec 8, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2001/0489
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system for monitoring intensity before, during, and after holographic exposure includes a monitoring assembly within an exposure beam and intermediate a light source and a hologram recording assembly. With the monitoring assembly in the exposure beam, a monitoring beam is produced that is directed towards detection elements located outside of the exposure beam. At the same time, the monitoring assembly allows the exposure beam to pass therethrough and onto the hologram recording assembly. The monitoring assembly may include a reflection hologram with an effective shape which is different from the supporting substrate, or glass substrates with an internal reflecting surface. In either event, the exposure beam remains undistorted. The spatial arrangement among the light source, hologram recording assembly, and detection elements are such that a reflected beam from the hologram recording assembly is directed away from the detection elements to avoid incorrect intensity monitoring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.