OPTICAL ADD DROP MULTIPLEXER

• US 20120002964A1
• Filed: 03/22/2011
• Published: 01/05/2012
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: TAKATSU, Kazuo, TAKEGUCHI, Koji
• Granted Patent: US 9,264,167 B2
• Time in Patent Office: Days
• US Class Current: 398/50
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• CPC Class Codes: H04J 14/0205 Select and combine arrangements, e.g. with an optical combiner at the output after adding or dropping
• CPC Class Codes: H04J 14/0209 Multi-stage arrangements, e.g. by cascading multiplexers or demultiplexers
• CPC Class Codes: H04J 14/021 Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM]
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]

Abstract

An optical add-drop multiplexer having first and second routes includes: an optical cross connect; a first multiplexer optically coupled to a plurality of output ports of the optical cross connect; a second multiplexer optically coupled to a plurality of other output ports of the optical cross connect; a first wavelength selective switch to generate a first WDM optical signal including an optical signal output from the first multiplexer and to guide the first WDM optical signal to the first route; and a second wavelength selective switch to generate a second WDM optical signal including optical signal output from the second multiplexer and to guide the second WDM optical signal to the second route.

Claims

1. An optical add-drop multiplexer having first and second routes, comprising:

an optical cross connect;

a first multiplexer optically coupled to a plurality of output ports of the optical cross connect;

a second multiplexer optically coupled to a plurality of other output ports of the optical cross connect;

a first wavelength selective switch to generate a first WDM optical signal including an optical signal output from the first multiplexer and to guide the first WDM optical signal to the first route; and

a second wavelength selective switch to generate a second WDM optical signal including an optical signal output from the second multiplexer and to guide the second WDM optical signal to the second route.

2. The optical add-drop multiplexer according to claim 1, wherein

the optical cross connect guides an input optical signal to the first multiplexer when the input optical signal is output on the first route, and guides an input optical signal to the second multiplexer when the input optical signal is output on the second route.

3. The optical add-drop multiplexer according to claim 1, wherein

the first and second multiplexers respectively have an optical coupler.

4. The optical add-drop multiplexer according to claim 3, further comprising

a plurality of optical filters respectively having a specified transmission wavelength, for a plurality of input ports of the optical cross connect.

5. The optical add-drop multiplexer according to claim 3, wherein

an optical coupler to combine a plurality of optical signals guided from a plurality of input ports of the optical cross connect is provided for each output port of the optical cross connect.

6. The optical add-drop multiplexer according to claim 1, wherein

the first and second multiplexers respectively have a wavelength multiplexer;

different transmission wavelengths are set for a plurality of input ports of the wavelength multiplexer; and

the optical cross connect guides an input optical signal of the optical cross connect to a corresponding input port of the wavelength multiplexer according to a wavelength of the input optical signal.

7. An optical add-drop multiplexer having first and second routes, comprising:

an optical cross connect;

a multiplexer optically coupled to a plurality of output ports of the optical cross connect;

an optical splitter to generate first and second split optical signals from an output optical signal of the multiplexer;

a first wavelength selective switch to generate a first WDM optical signal including an optical signal in the first split optical signal and to guide the first WDM optical signal to the first route;

a second wavelength selective switch to generate a second WDM optical signal including an optical signal in the second split optical signal and to guide the second WDM optical signal to the second route.

8. An optical add-drop multiplexer comprising:

an optical cross connect;

a drop signal generator to generate a drop optical signal from an input WDM optical signal;

an optical splitter to split the drop optical signal and to guide the drop optical signal to a plurality of input ports of the optical cross connect; and

a plurality of optical filters to extract a respectively specified wavelength from each drop optical signal output from the optical cross connect.

9. The optical add-drop multiplexer according to claim 8, wherein

the drop signal generator has a wavelength selective switch to generate the drop optical signal by selecting two or more wavelengths from the input WDM optical signal.

10. The optical add-drop multiplexer according to claim 9, wherein

the wavelength selective switch generates the drop optical signal by selecting first and second wavelengths from the input WDM optical signal;

and

a first optical filter of the plurality of optical filters extracts the first wavelength from the drop optical signal, and a second optical filter of the plurality of optical filters extracts the second wavelength from the drop optical signal.

11. The optical add-drop multiplexer according to claim 8, wherein

the drop signal generator splits the input WDM optical signal and outputs the split signal as the drop optical signal.

12. An optical add-drop multiplexer comprising:

a drop signal generator to generate a drop optical signal including two or more wavelengths in an input WDM optical signal;

an optical cross connect to split the drop optical signal and to guide the split drop optical signal to a plurality of output ports; and

a plurality of optical filters to extract a respectively specified wavelength from each drop optical signal output from the optical cross connect.

13. An optical add-drop multiplexer having first and second routes, comprising:

a plurality of optical cross connects;

a first optical splitter to split a first drop optical signal including an optical signal in a WDM optical signal input from the first route and to guide the first drop optical signal to the plurality optical cross connects;

a second optical splitter to split a second drop optical signal including an optical signal in a WDM optical signal input from the second route and to guide the second drop optical signal to the plurality optical cross connects; and

a plurality of optical filters to extract a respectively specified wavelength from the first and second drop optical signals output from the plurality of optical cross connects.

14. An optical add-drop multiplexer having first and second routes, comprising:

an optical coupler to combine an optical signal in a WDM optical signal input from the first route and an optical signal in a WDM optical signal input from the second route;

a wavelength demultiplexer to demultiplex an optical signal output from the optical coupler with respect to wavelength to generate a plurality of optical signals; and

an optical cross connect to switch a destination of the plurality of optical signals obtained by the wavelength demultiplexer.

15. An optical add method used in an optical add-drop multiplexer having first and second routes, comprising:

multiplexing a plurality of optical signals output from a plurality of output ports of an optical cross connect to generate a first multiplexed optical signal;

multiplexing a plurality of optical signals output from a plurality of other output ports of the optical cross connect to generate a second multiplexed optical signal;

generating a first WDM optical signal including an optical signal in the first multiplexed optical signal and guiding the first WDM optical signal to the first route; and

generating a second WDM optical signal including an optical signal in the second multiplexed optical signal and guiding the second WDM optical signal to the second route.

16. An optical add method used in an optical add-drop multiplexer having first and second routes, comprising:

multiplexing a plurality of optical signals output from a plurality of output ports of an optical cross connect to generate a multiplexed optical signal;

generating first and second split optical signals from the multiplexed optical signal;

generating a first WDM optical signal including an optical signal in the first split optical signal and guiding the first WDM optical signal to the first route; and

generating a second WDM optical signal including an optical signal in the second split optical signal and guiding the second WDM optical signal to the second route.

17. An optical drop method used in an optical add-drop multiplexer, comprising:

generating a drop optical signal from an input WDM optical signal;

splitting the drop optical signal and guiding the split drop optical signal to a plurality of input ports of an optical cross connect; and

extracting a respectively specified wavelength from each drop optical signal output from the optical cross connect.

18. An optical drop method used in an optical add-drop multiplexer having first and second routes, comprising:

splitting a first drop optical signal including an optical signal in a WDM optical signal input from the first route and guiding the split first drop optical signal to a plurality of optical cross connects;

splitting a second drop optical signal including an optical signal in a WDM optical signal input from the second route and guiding the split second drop optical signal to the plurality of optical cross connects; and

extracting an optical signal of a specified wavelength respectively from the first and second drop optical signals output from the plurality of optical cross connects.

19. An optical add-drop multiplexer having first and second routes, comprising:

a first optical cross connect;

a first multiplexer optically coupled to a plurality of output ports of the first optical cross connect;

a second multiplexer optically coupled to a plurality of other output ports of the first optical cross connect;

a first wavelength selective switch to generate a first WDM optical signal including an optical signal output from the first multiplexer and to guide the first WDM optical signal to the first route;

a second wavelength selective switch to generate a second WDM optical signal including an optical signal output from the second multiplexer and to guide the second WDM optical signal to the second route.

a second cross connect;

a drop signal generator to generate a drop optical signal from an input WDM optical signal from the first route or the second route;

an optical splitter to split the drop optical signal and to guide the drop optical signal to a plurality of input ports of the second optical cross connect; and

a plurality of optical filters to extract a respectively specified wavelength from each drop optical signal output from the second optical cross connect.

20. A WDM network system having a plurality of optical add-drop multiplexers, wherein

each optical add-drop multiplexer has first and second routes;

and

each optical add-drop multiplexer comprises;

a first optical cross connect;

a first multiplexer optically coupled to a plurality of output ports of the first optical cross connect;

a second multiplexer optically coupled to a plurality of other output ports of the first optical cross connect;

a first wavelength selective switch to generate a first WDM optical signal including an optical signal output from the first multiplexer and to guide the first WDM optical signal to the first route;

a second wavelength selective switch to generate a second WDM optical signal including an optical signal output from the second multiplexer and to guide the second WDM optical signal to the second route.

a second cross connect;

a drop signal generator to generate a drop optical signal from an input WDM optical signal from the first route or the second route;

an optical splitter to split the drop optical signal and to guide the drop optical signal to a plurality of input ports of the second optical cross connect; and

a plurality of optical filters to extract a respectively specified wavelength from each drop optical signal output from the second optical cross connect.