Low Cost Secure Submarine ROADM Branching Unit Using Bidirectional Wavelength-Selective Switch

Patent metadata

Field	Value
Publication number	US-2016149663-A1
Application number	US-201514938771-A
Country	US
Kind code	A1
Filing date	Nov 11, 2015
Priority date	Nov 21, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

A reconfigurable optical add/drop multiplexer (ROADM) unit includes a first optical circulator coupled to a first terminal; a second optical circulator coupled to a second terminal; a third optical circulator coupled to a third terminal; a fourth optical circulator coupled to a fourth terminal; a first wavelength-selective switch (WSS), coupled to the first, second, and third optical circulators; a second WSS coupled to the first, second, and fourth optical circulators, wherein the first and second WSSes are bidirectional operated; a first 1:2 coupler positioned between the first circulator and the first and second WSSes; a second 1:2 coupler positioned between the second circulator and the first and second WSSes.

First claim

What is claimed is:

1 . A system for communicating in a submarine transmission network, comprising:
first, second, third and fourth bi-directional terminals; and a reconfigurable optical add/drop multiplexer (ROADM) unit coupled to the terminals, including:
a first optical circulator coupled to the first terminal;
a second optical circulator coupled to the second terminal;
a third optical circulator coupled to the third terminal;
a fourth optical circulator coupled to the fourth terminal;
a first wavelength-selective switch (WSS), coupled to the first, second, and third optical circulators;
a second WSS coupled to the first, second, and fourth optical circulators, wherein the first and second WSSes are bidirectional operated;
a first 1:2 coupler positioned between the first circulator and the first and second WSSes;
a second 1:2 coupler positioned between the second circulator and the first and second WSSes.

2 . The system of claim 1 , wherein each optical circulator comprises a 3-port circulator.

3 . The system of claim 1 , wherein the first WSS is configured according to a wavelength plan and picks up only channels intended for the second Terminal and discards remaining channels.

4 . The system of claim 1 , wherein the WSSes select each individual channel to one of two inputs independently.

5 . The system of claim 1 , wherein input wavelength is assigned to avoid wavelength contention between the first to second channels and third to second channels.

6 . The system of claim 1 , wherein each WSS selects intended channels and discards dummy signals.

7 . The system of claim 1 , wherein both WSSes have a predetermined wavelength configuration, and two opposite direction operations of each WSS also have the predetermined wavelength configuration.

8 . The system of claim 1 , comprising a controller specifying symmetric wavelength assignments to the WSSes for simultaneous use in both directions.

9 . The system of claim 1 , wherein the ROADM unit is used in a submarine Branching Unit within the submarine transmission network.

10 . The system of claim 9 , comprising a power switched branching unit (PSBU) coupled to the ROADM unit.

11 . The system of claim 9 , comprising dummy lights for balancing power.

12 . The system of claim 1 , wherein the WSS comprises a 2×1 WSS.

13 . The system of claim 1 , wherein the circulators and WSSes are interconnected through optical fibers.

14 . A reconfigurable optical add/drop multiplexer (ROADM) unit, comprising:
a first optical circulator coupled to a first terminal; a second optical circulator coupled to a second terminal; a third optical circulator coupled to a third terminal; a fourth optical circulator coupled to a fourth terminal; a first wavelength-selective switch (WSS), coupled to the first, second, and third optical circulators; a second WSS coupled to the first, second, and fourth optical circulators, wherein the first and second WSSes are bidirectional operated; a first 1:2 coupler positioned between the first circulator and the first and second WSSes; a second 1:2 coupler positioned between the second circulator and the first and second WSSes.

Assignees

• Nec Lab America Inc

Inventors

• Ji Philip Nan
• Aida Ryuji
• Wang Ting

Classifications

• H04J14/0212 Primary

  using optical switches or wavelength selective switches [WSS] · CPC title

• H04Q11/0067

  Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring · CPC title

• H04Q2011/0086

  Network resource allocation, dimensioning or optimisation · CPC title

• H04B10/80

  Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water · CPC title

• H04Q2011/0016

  using wavelength multiplexing or demultiplexing · CPC title