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US 5,861,981 AGranted
Optical amplifier having dynamically shaped gain
AssigneeDitech Corporation
InventorSalim N. Jabr
Life of this patent
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AssigneeDitech Corporation
InventorSalim N. Jabr
Estimating the term…
A system and method are disclosed for adjusting the gain profile of an optical amplifier including a pump laser and an active gain element by selectively controlling the electron populations of at least one Stark sublevel of the electronic energy levels of the optical amplifier's active gain element. By dynamically controlling the electron populations of selected Stark sublevels the gain profile of the active gain element can be flattened. In a first method for controlling electron populations two-photon transitions are initiated between a pair of Stark sublevels of the same energy manifold of the active gain element. Two-photon transitions are stimulated by two additional pump lasers operating at wavelengths whose difference approximates the energy difference in the pair of Stark sublevels between which electrons are to be moved. In a second method for controlling electron populations single-photon transitions are initiated between a pair of Stark sublevels of different energy manifolds of the active gain element. Single-photon transitions are stimulated by an additional pump laser operating at a frequency difference that approximates the difference in the pair of energy levels. Alternatively, single photon transitions are stimulated by operating the amplifier's pump laser at a wavelength selected so as to simultaneously cause electron transitions from the ground level of the active gain element to one of the higher energy levels and electron transitions from a selected Stark sublevel of the upper laser level to a yet higher energy level.
An optical amplifier, comprising:
An optical amplifier, comprising:
In an optical amplifier including a pump laser, a light amplifying medium doped with an active gain element having an electronic ground energy level, a lower laser energy level, an upper laser level and a multiplicity of higher energy electronic levels, each electronic level having a multiplicity of energy sublevels, and a light guiding device for simultaneously guiding light from the pump laser and input signal light into the amplifying medium, a method of controlling the sublevel electron populations, comprising the step of:
In an optical amplifier including a pump laser, a light amplifying medium doped with an active gain element having an electronic ground energy level, a lower laser energy level, an upper laser level and a multiplicity of higher energy electronic levels, each the electronic level having a multiplicity of energy sublevels, and a light guiding device for simultaneously guiding light from the pump laser and input signal light into the amplifying medium, a method of controlling the sublevel populations, comprising the step of:
Dependencies are inferred from the claim text.