Optical node device and system including the device
First Claim
1. An optical node device applicable to an optical network including a closed loop provided by an optical fiber, comprising:
- a tunable wavelength selecting element adapted to input WDM signal light obtained by wavelength division multiplexing a plurality of optical signals having different wavelengths, the tunable wavelength selecting element having a function of dropping at least one optical signal from the WDM signal light and a function of adding at least one optical signal to at least one unassigned wavelength channel of the WDM signal light; and
a wavelength selecting filter optically connected to said tunable wavelength selecting element for removing noise present in any bands other than a signal band of each optical signal passing through said tunable wavelength selecting element.
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Accused Products
Abstract
Disclosed herein is an optical node device applicable to an optical network including a closed loop provided by an optical fiber. This optical node device includes a tunable wavelength selecting element adapted to input WDM signal light obtained by wavelength division multiplexing a plurality of optical signals having different wavelengths, the tunable wavelength selecting element having a function of dropping at least one optical signal from the WDM signal light and a function of adding at least one optical signal to at least one unassigned wavelength channel of the WDM signal light; and a wavelength selecting filter optically connected to the tunable wavelength selecting element for removing noise present in any bands other than a signal band of each optical signal passing through the tunable wavelength selecting element. With this configuration, the oscillation of optical power in the closed loop can be prevented by the use of the wavelength selecting filter for removing noise in any bands other than the signal band.
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Citations
28 Claims
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1. An optical node device applicable to an optical network including a closed loop provided by an optical fiber, comprising:
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a tunable wavelength selecting element adapted to input WDM signal light obtained by wavelength division multiplexing a plurality of optical signals having different wavelengths, the tunable wavelength selecting element having a function of dropping at least one optical signal from the WDM signal light and a function of adding at least one optical signal to at least one unassigned wavelength channel of the WDM signal light; and
a wavelength selecting filter optically connected to said tunable wavelength selecting element for removing noise present in any bands other than a signal band of each optical signal passing through said tunable wavelength selecting element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 19)
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15. A system comprising:
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a closed loop provided by an optical fiber; and
a plurality of optical node devices arranged along said closed loop;
at least one of said plurality of optical node device comprising;
a tunable wavelength selecting element adapted to input WDM signal light obtained by wavelength division multiplexing a plurality of optical signals having different wavelengths, said tunable wavelength selecting element having a function of dropping at least one optical signal from said WDM signal light and a function of adding at least one optical signal to at least one unassigned wavelength channel of said WDM signal light; and
a wavelength selecting filter optically connected to said tunable wavelength selecting element for removing noise present in any bands other than a signal band of each optical signal passing through said tunable wavelength selecting element.
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20. An optical node device applicable to an optical network including a closed loop provided by an optical fiber, comprising:
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an optical demultiplexer having an input port for inputting WDM signal light obtained by wavelength division multiplexing N (N is an integer satisfying 1<
N) optical signals having different wavelengths and N output ports for respectively outputting said N optical signals separated from said WDM signal light;
N 2×
2 optical switches each having first and second input ports and first and second output ports, said N optical signals output from said optical demultiplexer being supplied to said first input ports of said N 2×
2 optical switches, respectively, each of said N 2×
2 optical switches switching between a bar state where said first and second input ports are connected to said first and second output ports, respectively, and a cross state where said first and second input ports are connected to said second and first output ports, respectively; and
an optical multiplexer having N input ports for respectively inputting N optical signals output from said first output ports of said N 2×
2 optical switches, and an output port for outputting WDM signal light obtained by wavelength division multiplexing said N optical signals input to said N input ports. - View Dependent Claims (21, 22, 23, 24, 25, 26, 28)
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27. A system comprising:
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a closed loop provided by an optical fiber; and
a plurality of optical node devices arranged along said closed loop;
at least one of said plurality of optical node devices comprising;
an optical demultiplexer having an input port for inputting WDM signal light obtained by wavelength division multiplexing N (N is an integer satisfying 1<
N) optical signals having different wavelengths and N output ports for respectively outputting said N optical signals separated from said WDM signal light;
N 2×
2 optical switches each having first and second input ports and first and second output ports, said N optical signals output from said optical demultiplexer being supplied to said first input ports of said N 2×
2 optical switches, respectively, each of said N 2×
2 optical switches switching between a bar state where said first and second input ports are connected to said first and second output ports, respectively, and a cross state where said first and second input ports are connected to said second and first output ports, respectively; and
an optical multiplexer having N input ports for respectively inputting N optical signals output from said first output ports of said N 2×
2 optical switches, and an output port for outputting WDM signal light obtained by wavelength division multiplexing said N optical signals input to said N input ports.
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Specification