Signal light monitoring apparatus, optical amplification apparatus and optical reception apparatus, and signal light monitoring method
First Claim
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1. An apparatus comprising:
- an optical amplifier for amplifying an input light by excitation power;
a control unit controlling feeding of the excitation power to the optical amplifier; and
a signal light monitoring unit monitoring an input state of a signal light input into the optical amplifier, whereinthe signal light monitoring unit comprises;
an optical branching unit branching a branched light of light input into the optical amplifier in four directions;
a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit; and
a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit before outputting a result of the determination to the control unit, whereinthe control unit turns on feeding of the excitation power to the optical amplifier when the signal light is being input based on the result of the determination from the determination unit and turns off feeding of the excitation power to the optical amplifier when the signal light is not being input.
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Abstract
According to an aspect of an embodiment, an apparatus includes an optical branching unit for branching an input signal light in four directions, a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit, and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit.
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Citations
14 Claims
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1. An apparatus comprising:
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an optical amplifier for amplifying an input light by excitation power; a control unit controlling feeding of the excitation power to the optical amplifier; and a signal light monitoring unit monitoring an input state of a signal light input into the optical amplifier, wherein the signal light monitoring unit comprises; an optical branching unit branching a branched light of light input into the optical amplifier in four directions; a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit; and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit before outputting a result of the determination to the control unit, wherein the control unit turns on feeding of the excitation power to the optical amplifier when the signal light is being input based on the result of the determination from the determination unit and turns off feeding of the excitation power to the optical amplifier when the signal light is not being input.
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2. An apparatus, comprising:
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an optical demultiplexer demultiplexing a light input from a wavelength division multiplexing transmission line into a plurality of wavelength components; and optical amplification units provided as many as a number of wavelengths demultiplexed by the optical demultiplexer to amplify lights demultiplexed by the optical demultiplexer, wherein each optical amplification unit comprising; an optical amplifier for amplifying an input light by excitation power; a control unit controlling feeding of the excitation power to the optical amplifier; and a signal light monitoring unit monitoring an input state of a signal light input into the optical amplifier, wherein the signal light monitoring unit comprising; an optical branching unit branching a branched light of light input into the optical amplifier in four directions; a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit; and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit before outputting a result of the determination to the control unit, wherein the control unit turns on feeding of the excitation power to the optical amplifier when the signal light is being input based on the result of the determination from the determination unit and turns off feeding of the excitation power to the optical amplifier when the signal light is not being input. - View Dependent Claims (5)
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3. An apparatus, comprising:
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an optical amplifier for amplifying an input light by excitation power; a control unit controlling feeding of the excitation power to the optical amplifier; and a signal light monitoring unit monitoring an input state of a signal light input into the optical amplifier, wherein the signal light monitoring unit, comprising; a polarization state variation provider causing a polarization state of light input into the optical amplifier to cyclically vary; a polarizer extracting a linear polarization component in a specific direction from a branched light of light the polarization state of which is varied by the polarization state variation provider before being input into the optical amplifier; a power detector detecting power of light extracted by the polarizer; and a determination unit determining that the signal light is being input when cyclic variations resulting from variations of the polarization state caused by the polarization state variation provider is contained in power of light extracted by the polarizer based on a detection result from the power detector, and that the signal light is not being input when the cyclic variations are not contained, wherein the control unit turns on feeding of the excitation power to the optical amplifier when the signal light is being input based on the result of the determination from the determination unit and turns off feeding of the excitation power to the optical amplifier when the signal light is not being input.
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4. An apparatus, comprising:
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an optical demultiplexer demultiplexing a light input from a wavelength division multiplexing transmission line into a plurality of wavelength components; and optical amplification units provided as many as a number of wavelengths demultiplexed by the optical demultiplexer to amplify lights demultiplexed by the optical demultiplexer, wherein each optical amplification unit, comprising; an optical amplifier for amplifying an input light by excitation power; a control unit controlling feeding of the excitation power to the optical amplifier; and a signal light monitoring unit monitoring an input state of a signal light input into the optical amplifier, wherein the signal light monitoring unit, comprising; a polarization state variation provider causing a polarization state of light input into the optical amplifier to cyclically vary; a polarizer extracting a linear polarization component in a specific direction from a branched light of light the polarization state of which is varied by the polarization state variation provider before being input into the optical amplifier; a power detector detecting power of light extracted by the polarizer; and a determination unit determining that the signal light is being input when cyclic variations resulting from variations of the polarization state caused by the polarization state variation provider is contained in power of light extracted by the polarizer based on a detection result from the power detector, and that the signal light is not being input when the cyclic variations are not contained, wherein the control unit turns on feeding of the excitation power to the optical amplifier when the signal light is being input based on the result of the determination from the determination unit and turns off feeding of the excitation power to the optical amplifier when the signal light is not being input. - View Dependent Claims (6, 7, 8)
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9. A method comprising:
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extracting a plurality of polarization components having mutually different polarization parameters from a light; after extracting the plurality of polarization components, providing the light to an erbium doped fiber so that the provided light is amplified as the provided light travels through the erbium doped fiber; determining whether signal light is included in the provided light based on the extracted polarization components, to thereby provide a determination result; and controlling whether excitation light is fed to the erbium doped fiber to amplify the provided light as the provided light travels through the erbium doped fiber, in accordance with the determination result. - View Dependent Claims (10, 11, 12)
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13. An apparatus comprising:
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means for extracting a plurality of polarization components having mutually different polarization parameters from a light; means, after extracting the plurality of polarization components, for providing the light to an erbium doped fiber so that the provided light is amplified as the provided light travels through the erbium doped fiber; means for determining whether signal light is included in the provided light based on the extracted polarization components, to thereby provide a determination result; and means for controlling whether excitation light is fed to the erbium doped fiber to amplify the provided light as the provided light travels through the erbium doped fiber, in accordance with the determination result.
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14. A method comprising:
controlling feeding of excitation light an erbium doped fiber to thereby control amplification of input light traveling through the erbium doped fiber, in accordance with a determination of whether signal light is present in the input light based on polarization components having mutually different polarization parameters extracted from the input light.
Specification