US4674835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluoride glass optical fiber
Assignee: KDDI Corp
•
Filing: 1985-08-14
•
Granted: 1987-06-23
•
Expires: 2005-08-14
Abstract
Abstract In a fluoride glass optical fiber with extremely small transmission loss for infrared light having a core layer and a clad layer each consisting mainly of ZrF 4 - BaF 2 - LaF 3 - AlF 3 , NaF and H f F 4 are used as additives to obtain a desired refractive index difference between the core layer and the clad layer. The mixing ratio of the NaF to the H f F 4 satisfies the realtions; |0.25 ΔH.sub.f F.sub.4 -3ΔNaF|≦5, where ΔNaF is the difference between the amount (mol %) of the N a F to be added to the core layer and that to be added to the clad layer, and ΔH f F 4 to be added to the core layer and that to be added to the clad layer.
Inventors
- 👤 Yoshinori Mimura
- 👤 Hideharu Tokiwa
- 👤 Osamu Shinbori
- 👤 Tetsuya Nakai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:41
CPC Classifications
C; C03; C03C; C03C13/00; C03C13/04; C03C13/041; C03C13/042; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2929
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
124 words
A fluoride glass optical fiber for infrared light having a core layer and a clad layer each consisting mainly of ZrF 4 -BaF 2 -LaF 3 -AlF 3 , wherein NaF and H f F 4 are used as additives to obtain a desired refractive index difference between the core layer and the clad layer and to obtain for each layer a viscosity and a linear expansion coefficient which are suitable for drawing said optical fiber, both NaF and H f F 4 being present in at least one of the layers, and the total amount of NaF and H f F 4 in the clad layer being larger than the total amount of NaF and H f F 4 in the core layer.
Claim 2
Dependent Claim
124 words
A fluoride glass optical fiber for infrared light having a core layer and a clad layer each consisting mainly of ZrF 4 -BaF 2 -LaF 3 -AlF 3 , wherein NaF and H f F 4 are used as additives to obtain a desired refractive index difference between the core layer and the clad layer and to obtain for each layer a viscosity and a linear expansion coefficient which are suitable for drawing said optical fiber, both NaF and H f F 4 being present in at least one of the layers, and the total amount of NaF and H f F 4 in the clad layer being larger than the total amount of NaF and H f F 4 in the core layer.
Claim 3
Dependent Claim
80 words
A fluoride glass optical fiber according to claim 1, wherein the mixing ratio of said NaF and H f F 4 satisfies the equation; 0.25ΔH.sub.f F.sub.4 -ΔNaF<5 where ΔNaF is the difference between the amount (mol%) of the NaF added to the core layer and that added to the clad layer, and ΔH f F 4 is the difference between the amount (mol%) of H f F 4 added to the core layer and that added to the clad layer.
References Cited (Backward Citations)
JPS57166335A
Cited
US4445755A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |