Patent US4797143A successfully refreshed from Google Patents.
US4797143A
Expired / Lapsed
US
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Process for the production of optical fiber preforms
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1985-07-19
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Granted: 1989-01-10
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Expires: 2005-07-19
Abstract
Abstract An improved process for the production of optical fiber porous preforms of predetermined refractive index distribution by the vapor-phase deposition method is disclosed wherein a glass material and a dopant material are subjected to flame oxidation by the use of an oxyhydrogen burner to form fine glass particles which are deposited on one end of a supporting rod adapted to move apart from the oxyhydrogen burner while rotating to allow a rod-like porous preform to grow thereon. The improved process is characterized in that the correlation between the shape of the deposition face and the refractive index distribution is previously determined mathematically, and on a basis of the correlation therebetween, a process variable such as the distance between the porous preform and the burner is adjusted to produce the desired shape of the deposition face whereby there can be obtained an optimum refractive index distribution.
Inventors
- 👤 Kazunori Chida
- 👤 Hiroshi Yokota
- 👤 Michihisa Kyoto
- 👤 Hisao Sato
- 👤 Minoru Watanabe
- 👤 Naoki Yoshioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:17
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B2203/00; C03B2203/10; C03B2203/22
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
122 words
A process for producing an optical fiber porous preform having a predetermined refractive index distribution by a vapor-phase axial deposition method in which a glass material and a refractive index changing dopant material are subjected to flame oxidation by use of an oxyhydrogen burner to form fine glass particles deposited on one end of a supporting rod adapted to move apart from the oxyhydrogen burner while rotating to allow a rod-like porous preform to grow thereon, the improvement which comprises; determining a relationship between shape of the deposition face of the preform and refractive index and, controlling the shape of the deposition face of said preform during growth thereof to provide a predetermined refractive index to the preform based on said relationship.
Claim 2
Dependent Claim
122 words
A process for producing an optical fiber porous preform having a predetermined refractive index distribution by a vapor-phase axial deposition method in which a glass material and a refractive index changing dopant material are subjected to flame oxidation by use of an oxyhydrogen burner to form fine glass particles deposited on one end of a supporting rod adapted to move apart from the oxyhydrogen burner while rotating to allow a rod-like porous preform to grow thereon, the improvement which comprises; determining a relationship between shape of the deposition face of the preform and refractive index and, controlling the shape of the deposition face of said preform during growth thereof to provide a predetermined refractive index to the preform based on said relationship.
Claim 3
Dependent Claim
54 words
The process of claim 1 wherein the shape of the deposition face is continuously monitored during the process and when said shape deviates from a predetermined shape needed to provide a predetermined refractive index, at least one deposition face shape-affecting process variable is adjusted to correct said deviation, thereby to form said predetermined shape.
Claim 4
Dependent Claim
23 words
The process of claim 2 wherein the distance between the porous preform and the oxyhydrogen burner is adjusted to maintain said predetermined shape.
Claim 5
Dependent Claim
11 words
The process of claim 3 wherein the porous preform is moved.
Claim 6
Dependent Claim
11 words
The process of claim 3 wherein the oxyhydrogen burner is moved.
Claim 7
Dependent Claim
22 words
The process of claim 2 wherein the amount of gases discharged from the oxyhydrogen burner is controlled to maintain said predetermined shape.
Claim 8
Dependent Claim
16 words
The process of claim 3 wherein both the porous preform and the oxyhydrogen burner are moved.
Claim 9
Dependent Claim
111 words
The process of claim 1 wherein a correlation between a function approximately representing the shape of a deposition face on the end of the porous preform with the distance in radial direction from the center of the deposition face as a variable and a function representing the refractive index distribution in radial direction of the optical fiber preform with the distance in radial direction from the center of the optical fiber preform as a variable are determined and on the basis of the correlation between the two functions, the final shape of the deposition face is determined and the process is carried out until the deposition face has the final shape.
Claim 10
Dependent Claim
24 words
The process of claim 1 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
Claim 11
Dependent Claim
24 words
The process of claim 2 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
Claim 12
Dependent Claim
24 words
The process of claim 3 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
Claim 13
Dependent Claim
24 words
The process of claim 4 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
Claim 14
Dependent Claim
24 words
The process of claim 5 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
Claim 15
Dependent Claim
24 words
The process of claim 6 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
Claim 16
Dependent Claim
24 words
The process of claim 7 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
Claim 17
Dependent Claim
24 words
The process of claim 8 wherein as an additional process step, the optical fiber porous preform is consolidated to form an optical fiber preform.
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) | 1992-01-10 | 1992-07-11 | 1993-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-10 | 1996-07-11 | 1997-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-10 | 2000-07-11 | 2001-01-10 | $7700.00 | Window Closed / Lapsed |