Low noise high power optical fiber amplifier
AssigneeGeneral Instrument Corporation
InventorDavid R. Huber
Life of this patent
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Abstract
A rare earth doped optical fiber amplifier is pumped at a first wavelength selected to provide a low noise figure, and at a second wavelength selected to provide a high power efficiency. An erbium-doped fiber amplifier is illustrated, in which the first wavelength is about 980 nm and the second wavelength is about 1480 nm. The amplifier is forward pumped with the 980 nm wavelength adjacent the amplifier input to provide a low noise figure. Backward pumping at the 1480 nm wavelength is provided adjacent the amplifier output to achieve a high power efficiency.
Claims16
A rare earth doped optical fiber amplifier for use in optical communication systems comprising:
- a length of optical fiber doped with a rare earth element, said fiber having an input end and an output end;
- means for inputting an optical communication signal of a first wavelength to the input end of said fiber;
- means coupled closer to the input end of said fiber than to the output end thereof for pumping said fiber at a second wavelength selected to directly excite said rare earth element to provide a low noise figure;
- and
- means coupled closer to the output end of said fiber than to the input end thereof for pumping said fiber at a third wavelength that is longer than said second wavelength and is selected to directly excite said rare earth element to provide a high power efficiency.
A method of improving the noise figure and power efficiency of an optical fiber amplifier doped with a rare earth element for use in an optical communication system, comprising the steps of:
- pumping said fiber amplifier closer to an input end thereof than to an output end thereof at a first wavelength selected to directly excite said rare earth element to provide a low noise figure;
- and
- simultaneously pumping said amplifier closer to said output end thereof than to said input end thereof at a second wavelength that is longer than said first wavelength and is selected to directly excite said rare earth element to provide a high power efficiency.
Dependencies are inferred from the claim text.