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US 2004/0001249 A1Published application
Optical amplifier and optical fiber laser
AssigneeNEC Corporation
InventorYoshiyuki Yakabe
Life of this patent
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Abstract
An optical amplifier including : an erbium-doped amplifier medium, a first excitation generator and a second excitation generator. The first excitation generator is adopted to cause a first type excitation of the at least one kind of rare-earth ions to cause a population inversion between the laser upper level and the laser lower level. The second excitation generator is adopted to cause a second type excitation of the at least one kind of rare-earth ions from the excited state absorption lower level to a high excited level which is equal to or higher than the laser upper level.
Claims37
An optical amplifier including:
- an amplifier medium allowing a propagation of a signal light which is subject to an amplification, said amplifier medium being doped with at least one kind of rare-earth ions, and each of said at least one kind of rare-earth ions having an energy level system which includes:
- a ground level;
- a first pair of a laser upper level and a laser lower level which is higher than said ground level and lower than said laser upper level;
- and
- a second pair of an excited state absorption upper level, and an excited state absorption lower level which is lower than said excited state absorption upper level, wherein said second pair allows absorbing an emission light generated by a transition from said laser upper level to said laser lower level, and wherein said excited state absorption lower level is higher than said ground level and lower than said laser upper level, and wherein said excited state absorption lower level is different from said laser lower level;
- a first excitation generator for causing a first type excitation of said at least one kind of rare-earth ions to cause a population inversion between said laser upper level and said laser lower level;
- and
- a second excitation generator for causing a second type excitation of said at least one kind of rare-earth ions from said excited state absorption lower level to a high excited level which is equal to or higher than said laser upper level.
5 more elements
An optical amplifier including:
- an optical fiber waveguide comprising an amplifier medium which further comprises a fluorozirconate glass doped with erbium ions having an energy level system which includes:
- a ground level;
- a first pair of a laser upper level and a laser lower level which is higher than said ground level and lower than said laser upper level;
- and
- a second pair of an excited state absorption upper level, and an excited state absorption lower level which is lower than said excited state absorption upper level, wherein said second pair allows absorbing an emission light generated by a transition from said laser upper level to said laser lower level, and wherein said excited state absorption lower level is higher than said ground level and lower than said laser upper level, and wherein said excited state absorption lower level is different from said laser lower level;
- a first excitation generator which generates at least one of first type excitation lights which cause a first type excitation of said erbium ions to cause a population inversion between said laser upper level and said laser lower level;
- and
- a second excitation generator generates at least one of second type excitation lights which cause a second type excitation of said erbium ions from said excited state absorption lower level to a high excited level which is equal to or higher than said laser upper level, wherein said second type excitation lights are different in wavelength from said first type excitation lights.
5 more elements
A method of operating an optical amplifier which includes:
- an amplifier medium allowing a propagation of a signal light which is subject to an amplification, said amplifier medium being doped with at least one kind of rare-earth ions, and each of said at least one kind of rare-earth ions having an energy level system which includes:
- a ground level;
- a first pair of a laser upper level and a laser lower level which is higher than said ground level and lower than said laser upper level;
- and
- a second pair of an excited state absorption upper level, and an excited state absorption lower level which is lower than said excited state absorption upper level, wherein said second pair allows absorbing an emission light generated by a transition from said laser upper level to said laser lower level, and wherein said excited state absorption lower level is higher than said ground level and lower than said laser upper level, and wherein said excited state absorption lower level is different from said laser lower level,
- wherein said method includes:
- causing a first type excitation of said at least one kind of rare-earth ions to cause a population inversion between said laser upper level and said laser lower level;
- and
- causing a second type excitation of said at least one kind of rare-earth ions from said excited state absorption lower level to a high excited level which is equal to or higher than said laser upper level.
6 more elements
Dependencies are inferred from the claim text.