EP0143645A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical filters
Assignee: British Telecommunications PLC
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Filing: 1984-11-28
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Granted: —
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Expires: 2004-11-28
Abstract
Abstract An optical filter is formed between the end face of an optical fibre (11) and a glass plate (32). The end face of the fibre and the face surface of the plate (32) are coated with a highly reflective coating. The fibre and plate define a Fabry-Perot cavity which transmits a particular wavelength or narrow range of wavelengths which can be detected by a photodetector (15).
Inventors
- 👤 Stephen Robert Mallinson
- 👤 David John Mccartney
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-25 19:54
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4204; G02B6/4215; G02B6/26; G02B6/28; G02B6/293; G02B6/29346; G02B6/29358; G02B6/29379; G02B6/29395; G02F; G02F1/00; G02F1/01; G02F1/21; G02F1/213; G02F2203/00; G02F2203/05; G02F2203/055
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
33 words
An optical filter in which the end face of an optical fibre is spaced from a reflective surface to define a cavity which transmits only a particular wavelength or narrow range of wavelengths.
Claim 2
Dependent Claim
33 words
An optical filter in which the end face of an optical fibre is spaced from a reflective surface to define a cavity which transmits only a particular wavelength or narrow range of wavelengths.
Claim 3
Dependent Claim
22 words
An optical filter as claimed in claim 1, wherein the reflective surface is provided by a reflective coating on a glass plate.
Claim 4
Dependent Claim
21 words
An optical filter as claimed in claim 1 or claim 2, wherein the optical path length of the cavity is variable.
Claim 5
Dependent Claim
31 words
An optical filter as claimed in claim 3, wherein the optical path length of the cavity is variable by varying the spacing between the fibre end face and the reflective surface.
Claim 6
Dependent Claim
20 words
An optical filter as claimed in any preceding claim, including a photodetector arranged to receive light transmitted through the cavity.
Claim 7
Dependent Claim
18 words
An optical filter as claimed in any preceding claim wherein the optical fibre is a monomode optical fibre.
Claim 8
Dependent Claim
28 words
An optical filter as claimed in any preceding claim wherein the reflective surface is provided by a reflective coating on an end face of a multimode optical fibre.
Claim 9
Dependent Claim
20 words
An optical filter as claimed in any preceding claim wherein the optical path length of the cavity is varied electro-optically.
References Cited (Backward Citations)
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