Patent EP0283748A1 successfully refreshed from Google Patents.
EP0283748A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical fiber
Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1988-02-24
•
Granted: —
•
Expires: 2008-02-24
Abstract
Abstract An optical fiber comprising a core (11) at least a center portion of which is made of glass essentially consisting of silica, a first cladding (12) which is provided around the core (11) and has a refractive index smaller than that of the core (11) and a second cladding (13) which is provided around the first cladding (12) and has a refractive index larger than that of the first cladding (12) and lower than that of the core (11), which has improved environmental resistance and small wavelength dispersion in a wide range of wavelength.
Inventors
- 👤 Masayuki Yokohama Works Of Sumitomo Shigematsu
- 👤 Shigeru Yokohama Works Of Sumitomo Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 13:56
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/02; G02B6/036; G02B6/03616; G02B6/03638; G02B6/03644; C; C03; C03C; C03C13/00; C03C13/04; C03C13/045; G02B6/02214; G02B6/02219; G02B6/02228; G02B6/02233; G02B6/03622; G02B6/03627; C03B; C03B2203/00; C03B2203/36
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
71 words
An optical fiber comprising a core at least a center portion of which is made of glass essentially consisting of silica, a first cladding which is provided around the core and has a refractive index smaller than that of the core and a second cladding which is provided around the first cladding and has a refractive index larger than that of the first cladding and lower than that of the core.
Claim 2
Dependent Claim
71 words
An optical fiber comprising a core at least a center portion of which is made of glass essentially consisting of silica, a first cladding which is provided around the core and has a refractive index smaller than that of the core and a second cladding which is provided around the first cladding and has a refractive index larger than that of the first cladding and lower than that of the core.
Claim 3
Dependent Claim
30 words
The optical fiber according to claim 1, wherein an inner part of the second cladding has a refractive index higher than that of an outer part of the second cladding.
Claim 4
Dependent Claim
63 words
The optical fiber according to claim 1, wherein Δ₁ = 0.9 to 1.2 %, Δ₁ - Δ₂ = 0.2 to 0.6 % and Ratio of radius of the core to that of the first cladding = 0.3 to 0.7 wherein Δ₁ and Δ₂ are refractive index differences between the core and the first cladding and between the core and the second cladding, respectively.
References Cited (Backward Citations)
US4447125A
Cited
US4435040A
Cited
US4447127A
Cited
EP0131634A1
Cited
EP0164681A2
Cited
DE3500672A1
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.