US4139262A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter for a light wave in a light guiding fiber
Assignee: Siemens AG
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Filing: 1977-01-12
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Granted: 1979-02-13
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Expires: 1997-01-12
Abstract
Abstract A filter comprising multiple cylindrical layers of alternately high- and low-refractive materials and surrounded by a light-absorbent material with an outer diffusing surface is deposited by evaporation about a short axial length of a glass fiber to polarize or spectrum-filter light passing through said fiber. The indices of refraction of the filter layers are higher than the effective guide indices of the modes of the fiber core.
Inventors
- 👤 Hans Mahlein
- 👤 Gerhard Winzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:12
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B6/00; G02B6/02; G02B6/02052; G02B6/036; G02B6/02295; G02B6/023; G02B6/03616; G02B6/03661; G02B6/03694
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
A filter system for an optic fiber, the system comprising: an optic fiber having an axial length and an index of refraction n f ; a multi-layer filter means circumferentially surrounding said optic fiber along an axial portion thereof and not interrupting said fiber, the filter being comprised of alternate layers of materials having high and low indices of refraction n 1H ; and n 1L ; and wherein the indices of refraction of the fiber and the layers are related by N < n.sub.1L < n.sub.1H and wherein N is the effective guide index of guided modes of light in the fiber N = n.sub.f sin θ, wherein θ is the zigzag angle of the guided modes in the fiber; and said multi-layer filter means refracting and reflecting desired light components back into the fiber and absorbing undesired components.
Claim 2
Dependent Claim
140 words
A filter system for an optic fiber, the system comprising: an optic fiber having an axial length and an index of refraction n f ; a multi-layer filter means circumferentially surrounding said optic fiber along an axial portion thereof and not interrupting said fiber, the filter being comprised of alternate layers of materials having high and low indices of refraction n 1H ; and n 1L ; and wherein the indices of refraction of the fiber and the layers are related by N < n.sub.1L < n.sub.1H and wherein N is the effective guide index of guided modes of light in the fiber N = n.sub.f sin θ, wherein θ is the zigzag angle of the guided modes in the fiber; and said multi-layer filter means refracting and reflecting desired light components back into the fiber and absorbing undesired components.
Claim 3
Dependent Claim
16 words
A filter system as defined in cliam 1, wherein the filter serves as a polarization filter.
Claim 4
Dependent Claim
16 words
A filter system as defined in cliam 1, wherein the filter serves as a polarization filter.
Claim 5
Dependent Claim
33 words
A filter system as defined in claim 1, wherein the filter layers each have an effective thickness equal to one-quarter of the wave length of a light to be guided in the fiber.
Claim 6
Dependent Claim
18 words
A filter sytem as defined in claim 1, wherein the filter layers are surrounded by an absorbent material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-12 | 1982-08-14 | 1983-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-12 | 1986-08-14 | 1987-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-12 | 1990-08-14 | 1991-02-13 | $7700.00 | Window Closed / Lapsed |