EP0349309B1
Expired / Lapsed
EP
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Birefringence diffraction grating type polarizer
Assignee: NEC Corp
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Filing: 1989-06-29
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Granted: 1993-10-27
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Expires: 2009-06-29
Abstract
No abstract record available.
Inventors
- 👤 Yutaka C/O Nec Corporation Urino
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:42
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/18; G02B5/1833; G02B5/30; G02B5/3083; G02B6/00; G02B6/10; G02B6/12; G02B6/122; G02B6/124
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
76 words
A birefringence diffraction grating type polarizer, comprising: an optically anisotropic sheet crystal substrate (1) provided with periodical ion-exchanged regions (3) on one surface thereof to form an optical diffraction grating; said polarizer being characterised by a dielectric layer (4) on each of said ion-exchanged regions; and a metal diffusion layer (2) created by diffusion of metal into said one surface of said crystal substrate at least within regions where ion-exchange is effected on said crystal substrate.
Claim 2
Dependent Claim
29 words
A birefringence diffraction grating type polarizer as defined in claim 1, wherein said metal diffusion layer is provided on the whole of said one surface of said crystal substrate.
Claim 3
Dependent Claim
20 words
A birefringence diffraction grating type polarizer as defined in claim 1, wherein said crystal substrate is composed of lithium niobate.
Claim 4
Dependent Claim
26 words
A birefringence diffraction grating type polarizer as defined in claim 1, wherein said metal is selected from the group consisting of titanium, copper, nickel and vanadium.
Claim 5
Dependent Claim
19 words
A birefringence diffraction grating type polarizer as defined in claim 1, wherein said dielectric layer is composed of quartz.
Claim 6
Dependent Claim
19 words
A birefringence diffraction grating type polarizer as defined in claim 1, wherein said ion-exchanged region is a proton-exchanged region.
Claim 7
Dependent Claim
54 words
A birefringence diffraction grating type polarizer as defined in claim 1, wherein a depth of said ion-exchanged region and a thickness of said dielectric layer is selected so as to cause the zero-order diffraction efficiency for the extraordinary ray to be zero and the zero-order diffraction efficiency for the ordinary ray to be 1.
References Cited (Backward Citations)
No citation records indexed.
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