Patent US4832720A successfully refreshed from Google Patents.
US4832720A
Expired / Lapsed
US
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Method for producing multi-core optical fiber
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1987-09-28
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Granted: 1989-05-23
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Expires: 2007-09-28
Abstract
Abstract A multi-core optical fiber with improved dimensional accuracy is produced by a method comprising inserting at least two core glass rods in bores formed in a cladding glass rod having a refractive index lower than that of the core glass rods to be inserted, heating a composite of the cladding glass rod and the core glass rods to integrate them together, and drawing the integrated composite to fabricate a multi-core optical fiber. The drawing may be carried out simultaneously with the integration step.
Inventors
- 👤 Minoru Watanabe
- 👤 Hiroshi Yokota
- 👤 Shuzo Suzuki
- 👤 Hiroshi Suganuma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:42
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/01205; C03B37/01211; C03B37/01222; C03B37/02; C03B37/025; C03B37/027; C03B2203/00; C03B2203/34
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
72 words
A method for producing a multi-core optical fiber comprising: inserting at least two core glass rods in bores formed in a cladding glass rod having a lower refractive index and a lower softening point than that of the core glass rods to be inserted, heating a composite of said cladding glass rod and said core glass rods to integrate them together, and drawing the integrated composite to fabricate a multi-core optical fiber.
Claim 2
Independent Claim
72 words
A method for producing a multi-core optical fiber comprising: inserting at least two core glass rods in bores formed in a cladding glass rod having a lower refractive index and a lower softening point than that of the core glass rods to be inserted, heating a composite of said cladding glass rod and said core glass rods to integrate them together, and drawing the integrated composite to fabricate a multi-core optical fiber.
Claim 3
Dependent Claim
29 words
The method according to claim 1, wherein said cladding glass rod is made of quartz glass containing fluorine and said core glass rod is made of pure quartz glass.
Claim 4
Independent Claim
80 words
A method for producing a multi-core optical fiber comprising the steps of: inserting at least two core glass rods consisting essentially of SiO 2 in bores formed in a cladding glass rod having a lower refractive index and a lower softening point than that of the core glass rods to be inserted, heating a composite of said cladding glass rod and said core glass rods to integrate them together, and drawing the integrated composite to fabricate a multi-core optical fiber.
Claim 5
Independent Claim
80 words
A method for producing a multi-core optical fiber comprising the steps of: inserting at least two core glass rods consisting essentially of SiO 2 in bores formed in a cladding glass rod having a lower refractive index and a lower softening point than that of the core glass rods to be inserted, heating a composite of said cladding glass rod and said core glass rods to integrate them together, and drawing the integrated composite to fabricate a multi-core optical fiber.
Claim 6
Independent Claim
82 words
A method for producing a multi-core optical fiber comprising the steps of: inserting at least two core glass rods consisting essentially of SiO 2 -GeO 2 in bores formed in a cladding glass rod having a lower refractive index and a lower softening point than that of the core glass rods to be inserted, heating a composite of said cladding glass rod and said core glass rods to integrate them together, and drawing the integrated composite to fabricate a multi-core optical fiber.
Claim 7
Independent Claim
82 words
A method for producing a multi-core optical fiber comprising the steps of: inserting at least two core glass rods consisting essentially of SiO 2 -GeO 2 in bores formed in a cladding glass rod having a lower refractive index and a lower softening point than that of the core glass rods to be inserted, heating a composite of said cladding glass rod and said core glass rods to integrate them together, and drawing the integrated composite to fabricate a multi-core optical fiber.
References Cited (Backward Citations)
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JPS5737539A
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EP0147225A2
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JPS60155543A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-22 | 1992-11-21 | 1993-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-22 | 1996-11-21 | 1997-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-22 | 2000-11-21 | 2001-05-23 | $7700.00 | Window Closed / Lapsed |