EP0427320A2
Expired / Lapsed
EP
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Active-fiber optical amplifier having a wide pumping band and related active fiber
Assignee: Pirelli and C SpA
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Filing: 1990-10-30
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Granted: —
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Expires: 2010-10-30
Abstract
Abstract The invention relates to an optical amplifier, in particular for optical fiber telecommunications lines, comprising an erbium-doped laser-emission active optical fiber and a luminous pumping laser source operating at a predetermined wavelength, in which the active optical fiber comprises ytterbium as the further dopant, which exhibits an absorption of light at the emission wavelength of a pumping laser emitter. for example a commercially available three-level diode-pumped laser of the Nd:YAG type, operating between 900 and 950 nm, which is different from the wavelength at which erbium alone can be pumped, and which is adapted to transfer the energy thus absorbed to the erbium contained in the fiber. thereby causing a population inversion thereof adapted to generate a stimulated light emission in the presence of an optical transmission signal. The use of ytterbium in the active fiber enables the achievement of a sufficiently wide spectrum of absorption, such that the use of a laser of high power and low cost for the active fiber pumping within the amplifier is made possible.
Inventors
- 👤 Giorgio Grasso
- 👤 Aldo Righetti
- 👤 Flavio Fontana
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 15:06
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/09; H01S3/091; H01S3/094; H01S3/094003; H01S3/05; H01S3/06
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
120 words
An optical fiber, particularly for use in optical fiber amplifiers for optical telecommunications lines, containing erbium as the laser-emission dopant and having a dopant acting as a variator of refractive index adapted to ensure a waveguide effect, to be fed by a luminous pumping source of predetermined wavelength for generating said laser emission, characterized in that the fiber comprises a further dopant having a significant absorption of luminous energy at the emission wavelength of a pumping laser in an optical amplifier incorporating the fiber, said further dopant being adapted to transfer the absorbed pumping energy to the erbium contained in the fiber, thereby causing a population inversion generating a stimulated luminous emission in the presence of an optical transmission signal.
Claim 2
Dependent Claim
120 words
An optical fiber, particularly for use in optical fiber amplifiers for optical telecommunications lines, containing erbium as the laser-emission dopant and having a dopant acting as a variator of refractive index adapted to ensure a waveguide effect, to be fed by a luminous pumping source of predetermined wavelength for generating said laser emission, characterized in that the fiber comprises a further dopant having a significant absorption of luminous energy at the emission wavelength of a pumping laser in an optical amplifier incorporating the fiber, said further dopant being adapted to transfer the absorbed pumping energy to the erbium contained in the fiber, thereby causing a population inversion generating a stimulated luminous emission in the presence of an optical transmission signal.
Claim 3
Dependent Claim
23 words
An optical fiber according to claim 1, characterized in that the further dopant consists of ytterbium in the form of a trivalent cation.
Claim 4
Dependent Claim
51 words
An optical fiber according to claim 2, characterized in that the concentration of ytterbium in the fiber relative to the contained erbium, expressed as percent by weight of the contained oxides is: and the concentration of ytterbium by weight relative to the overall weight of the fiber is lower than 5%.
Claim 5
Dependent Claim
28 words
An optical fiber according to claim 3, characterized in that the concentration of ytterbium by weight relative to the overall weight of the fiber is lower the 1%.
Claim 6
Dependent Claim
21 words
An optical fiber according to claim 1, characterized in that the dopant capable of varying the index of refraction is germanium.
Claim 7
Dependent Claim
21 words
An optical fiber according to claim 1, characterized in that the dopant capable of varying the index of refraction is aluminium.
Claim 8
Dependent Claim
90 words
An optical amplifier, in particular for optical fiber telecommunications lines, comprising an erbium-doped laser-emission active optical fiber and a luminous pumping laser source, operating at a predetermined wavelength, characterized in that the active optical fiber comprises a further dopant exhibiting a light absorption at the emission wavelength of the pumping laser emitter and is adapted to transfer the absorbed energy to the erbium contained in the fiber, thereby causing a population inversion of the same, adapted to generate a stimulated light emission in the presence or an optical transmission signal.
Claim 9
Dependent Claim
90 words
An optical amplifier, in particular for optical fiber telecommunications lines, comprising an erbium-doped laser-emission active optical fiber and a luminous pumping laser source, operating at a predetermined wavelength, characterized in that the active optical fiber comprises a further dopant exhibiting a light absorption at the emission wavelength of the pumping laser emitter and is adapted to transfer the absorbed energy to the erbium contained in the fiber, thereby causing a population inversion of the same, adapted to generate a stimulated light emission in the presence or an optical transmission signal.
Claim 10
Dependent Claim
52 words
An optical amplifier according to claim 7, characterized in that the further dopant in the active optical fiber consists of ytterbium in the form of a trivalent cation and the luminous pumping source is a three-level diode-pumped laser of the neodymium:YAG type or a semiconductor-diode laser operating between 900 and 950 nm.
Claim 11
Dependent Claim
63 words
An optical amplifier according to claim 7, characterized in that the concentration of ytterbium in the active optics fiber of the amplifier with respect to the concentration of the contained erbium, expressed as percent by weight of the oxides contained in said fiber is: and the concentration by weight of ytterbium relative to the overall weight of the fiber is lower than 5%.
Claim 12
Dependent Claim
18 words
An optical amplifier according to claim 9, characterized in that the concentration of ytterbium is lower than 1%.
References Cited (Backward Citations)
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