发明名称 |
OPTICAL RADIATION DEVICES |
摘要 |
A device, particularly an antenna device, for emitting a beam of optical radiation to irradiate a remote target area. The device includes an optical source (10) having a limited wavelength band, and a hologram pattern (14) positioned in the path of a light beam originating from the source, the pattern being selected to produce a composite beam (20) 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 (10) 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. |
申请公布号 |
WO9402873(A1) |
申请公布日期 |
1994.02.03 |
申请号 |
WO1993GB01591 |
申请日期 |
1993.07.28 |
申请人 |
BRITISH TELECOMMUNICATIONS PUBLIC LIMITED COMPANY |
发明人 |
WOOD, DAVID, CHARLES;SMYTH, PETER, PAUL |
分类号 |
G02B5/32;G02B27/00;G03H1/08;G03H1/18;G03H1/26;H04B10/112;(IPC1-7):G02B27/00;H04B10/10 |
主分类号 |
G02B5/32 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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