Optical switching device and communications system

• US 8,712,238 B2
• Filed: 08/25/2011
• Issued: 04/29/2014
• Est. Priority Date: 11/12/2010
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Sakamoto, Takeshi
• Primary Examiner(s): Vanderpuye, Ken
• Assistant Examiner(s): Alagheband, Abbas H
• Application Number:
  US13/218,069
• Publication Number:
  US 20120121255A1
• Time in Patent Office: 978 Days
• Field of Search: 398/34, 398/48, 398/50, 398/83
• US Class Current: 398/34
• CPC Class Codes: H04B 10/2939 Network aspects
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04J 14/02216 by gain equalization
• CPC Class Codes: H04J 14/0275 using an optical service channel
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget

Abstract

An optical switching device includes a optical add/drop multiplexer that at least adds an optical signal into and/or drops an optical signal from wavelength division multiplexed light that is wavelength division multiplexed optical signals; a plurality of amplifiers that are disposed on optical paths included in the optical add/drop multiplexer and that can use supplied pump light to amplify the optical signals; an optical source that generates the pump light; and an optical switch that supplies the generated pump light to any one of the amplifiers.

Claims

1. An optical switching device comprising:

a optical add/drop multiplexer that at least adds an optical signal into and/or drops an optical signal from wavelength division multiplexed light that is wavelength division multiplexed optical signals;

a plurality of amplifiers that are disposed on optical paths included in the optical add/drop multiplexer and that can use supplied pump light to amplify the optical signals;

an optical source that generates the pump light;

an optical switch that supplies the generated pump light to any one of the amplifiers; and

a controller that identifies an amplifier whose power of an internal laser diode (LD) is insufficient among the amplifiers and controls the optical source and the optical switch such that the pump light is supplied to the identified amplifier.

2. The optical switching device according to claim 1, wherein

the optical add/drop multiplexer includes a wavelength selective switch that distributes the wavelength division multiplexed light among the optical paths, according to wavelength, and

the amplifiers are disposed on the optical paths respectively.

3. The optical switching device according to claim 1, comprising a plurality of the optical sources, wherein

the optical switch supplies the pump light generated by the optical sources to any one of the amplifiers.

4. The optical switching device according to claim 1, wherein the optical switch is an optical cross connect that connects the optical source and the amplifiers.

5. The optical switching device according to claim 3, wherein the optical sources are of a number less than the number of amplifiers.

6. The optical switching device according to claim 1, wherein the controller acquires a wavelength count for each of the optical signals input to the amplifiers and based on the acquired wavelength counts, identifies the amplifier whose amplification capacity is insufficient.

7. The optical switching device according to claim 1, wherein the controller acquires change information indicating a change in the wavelength count of an optical signal and based on the acquired change information, controls the optical source and the optical switch before the change.

8. The optical switching device according to claim 1, wherein

the optical add/drop multiplexer includes a wavelength selective switch that distributes the optical signals among the optical paths, according to wavelength, and

the controller acquires a wavelength count for each of the optical signals distributed among the optical paths by the wavelength selective switch and based on the acquired wavelength counts, identifies the amplifier whose amplification capacity is insufficient.

9. The optical switching device according to claim 1, wherein

the amplifiers respectively amplify the optical signals, using internal pump light generated by an internal optical source, and

the controller acquires pump power information that indicates the power of the internal pump light of the amplifiers and based on the acquired pump power information, identifies the amplifier whose amplification capacity is insufficient.

10. The optical switching device according to claim 1, wherein the controller acquires output power information that indicates the power of the optical signals output by the amplifiers and based on the acquired output power information, identifies the amplifier whose amplification capacity is insufficient.

11. The optical switching device according to claim 1, comprising a plurality of receivers that receive the optical signals split by the optical add/drop multiplexer, wherein

the controller identifies among the receivers, a receiver for which reception power of the optical signal is below a threshold and identifies among the amplifiers, the amplifier that corresponds to the identified receiver.

12. The optical switching device according to claim 1, wherein

among the amplifiers, if an amplifier has insufficient amplification capacity, the amplifier transmits a request signal, and

the optical switching device further comprises a controller that controls the optical source and the optical switch such that the pump light is supplied to the amplifier that has transmitted the request signal.

13. The optical switching device according to claim 1, wherein the amplifiers respectively amplify the optical signals, using internal pump light generated by an internal optical source and if the pump light is supplied via the optical switch, the amplifiers adjust the ratio of the power of the pump light supplied via the optical switch and the power of the internal pump light to a given ratio.

14. The optical switching device according to claim 1, wherein

the optical add/drop multiplexer includes a wavelength selective switch that selects and couples according to wavelength, the optical signals output from the optical paths, and

the amplifiers are respectively disposed on the optical paths.

15. The optical switching device according to claim 1, wherein the amplifiers respectively include:

an input port to which the pump light is supplied, and

an amplifier medium that transmits the pump light input to the input port and the optical signal.

16. A communications system comprising:

a plurality of connected optical switching devices that respectively include;

a optical add/drop multiplexer that at least adds an optical signal into and/or drops an optical signal from wavelength division multiplexed light that is wavelength division multiplexed optical signals;

a plurality of amplifiers that are disposed on optical paths included in the optical add/drop multiplexer and that can use supplied pump light to amplify the optical signals;

an optical source that generates the pump light;

an optical switch that supplies the generated pump light to any one of the amplifiers; and

a controller that identifies an amplifier whose power of an internal laser diode (LD) is insufficient among the amplifiers and controls the optical source and the optical switch such that the pump light is supplied to the identified amplifier, wherein

the communications system transmits the wavelength division multiplexed light.