Optical radiation devices
US5757523A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 1995 |
| Grant date | May 26, 1998 |
| Priority date | — |
| Expiry date | Mar 2, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/1121
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A device, particularly an antenna device, for emitting a beam of optical radiation to irradiate a remote target area includes an optical source having a limited wavelength band, and a hologram pattern positioned in the path of a light beam originating from the source, the pattern being selected to produce a composite beam having a predetermined shape or far field pattern conforming to the target area and/or a predetermined distribution of light intensity in the target area. Where the optical source is a point source, the hologram pattern selectively retards the phase of respective components of the incident wavefront to produce a composite beam having a far field pattern that precludes focusing of the beam into a single small spot. The device has particular application in a telecommunication system wherein a data signal is transmitted through free space by an optical beam, at least one characteristic of the beam being controlled by the hologram pattern in the path of the beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.