Transponder Aggregator Without Wavelength Selector for Colorless and Directionless Multi-Degree ROADM Node

• US 20110286746A1
• Filed: 10/07/2010
• Published: 11/24/2011
• Est. Priority Date: 10/09/2009
• Status: Abandoned Application

• Current Assignee: NEC Laboratories America Inc (NEC Corporation)
• Original Assignee: NEC Laboratories America Inc (NEC Corporation)
• Inventors: Aono, Yoshiaki, Yu, Jianjun, Ji, Philip Nan, Wang, Ting, Shibutani, Makoto, Tajima, Tsutomu
• Application Number:
  US12/900,220
• Publication Number:
  US 20110286746A1
• Time in Patent Office: Days
• US Class Current: 398/83
• 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 14/021 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]
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0219 Modular or upgradable architectures

Abstract

A method for transponder optical channel selection of optical signals from a transponder aggregator includes choosing wavelength division multiplexing channels to be dropped from a transponder aggregator receiving optical input signals, splitting all dropped wavelength division multiplexing channels into at least one transponder having a coherent receiver and transmitter, and tuning a local oscillator laser of the coherent receiver to a wavelength of one of the all dropped wavelength division multiplexing channels for selecting one of the all dropped wavelength division multiplexing channels.

Claims

1. A method for transponder optical channel selection of optical signals from a transponder aggregator, said method comprising the steps of:

choosing wavelength division multiplexing channels to be dropped from a transponder aggregator receiving optical input signals;

splitting all dropped wavelength division multiplexing channels into at least one transponder having a coherent receiver and transmitter; and

tuning a local oscillator laser of said coherent receiver to a wavelength of one of said all dropped wavelength division multiplexing channels for selecting one of said all dropped wavelength division multiplexing channels.

2. The method of claim 1, wherein said step of choosing comprises a wavelength selector switch for selecting said wavelength division multiplexing channels to be dropped.

3. The method of claim 1, wherein said tuning comprises mixing said all dropped wavelength division multiplexed channels with a continuous wave signal from said local oscillator.

4. The method of claim 1, wherein said tuning comprises tuning said local oscillator laser to a wavelength corresponding to one of said all dropped wavelength division multiplexing channels for being received by a coherent mixer.

5. The method of claim 1, wherein said tuning comprises producing different vectorial additions of said local oscillator laser and one of said all dropped wavelength division multiplexing channels.

6. The method of claim 5, wherein said tuning comprises detecting different vectorial additions of said local oscillator laser tuned to a wavelength of one of said all dropped wavelength division multiplexing channels by an array of photodetectors for recovering data from one of said all dropped wavelength division multiplexing channels

7. The method of claim 6, wherein said photodetectors are one of single-ended photodetectors and balanced photodetectors.

8. The method of claim 4, wherein said coherent mixer comprises balanced outputs.

15. The optical configuration of claim 4, wherein said coherent receiver comprises a mixer having balanced output.

9. An optical configuration comprising:

a transponder aggregator for choosing wavelength division multiplexing channels to be dropped responsive to received input signals; and

at least one transponder coupled to said transponder aggregator and having a coherent receiver and transmitter, said transponder selecting one of said wavelength division multiplexing channels dropped through tuning of a local oscillator laser in said coherent receiver to a wavelength of one of said wavelength division multiplexing channels dropped.

10. The optical configuration of claim 9, wherein said transponder aggregator comprises a wavelength selector switch for choosing said wavelength division multiplexing channels to be dropped.

11. The optical configuration of claim 9, wherein coherent receiver comprises a mixer for mixing said dropped wavelength division multiplexed channels with a continuous wave signal from said local oscillator.

12. The optical configuration of claim 9, wherein said mixing produces different vectorial additions of said local oscillator laser and one of said dropped wavelength division multiplexing channels.

13. The optical configuration of claim 12, wherein said coherent receiver detects different vectorial additions of said local oscillator laser tuned to a wavelength of one of said dropped wavelength division multiplexing channels by an array of photodetectors for recovering data from one of said dropped wavelength division multiplexing channels.

14. The optical configuration of claim 13, wherein said photodetectors are one of single-ended photodetectors and balanced photodetectors.