Versatile optical switching for wavelength-division multiplexed system

• US 20020041412A1
• Filed: 12/18/2001
• Published: 04/11/2002
• Est. Priority Date: 05/26/2000
• Status: Active Grant

• Current Assignee: Versatile Optical Networks, Inc. (Microchip Technology Incorporated)
• Original Assignee: Versatile Optical Networks, Inc. (Microchip Technology Incorporated)
• Inventors: Jain, Amit, Hajjar, Roger A.
• Granted Patent: US 6,535,312 B2
• Time in Patent Office: Days
• US Class Current: 398/87
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0219 Modular or upgradable architectures
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0011 using wavelength conversion
• CPC Class Codes: H04Q 2011/0013 using gating amplifiers
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0041 Optical control
• CPC Class Codes: H04Q 2011/0043 Fault tolerance
• CPC Class Codes: H04Q 2011/0045 Synchronisation
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget
• CPC Class Codes: H04Q 2011/0052 Interconnection of switches
• CPC Class Codes: H04Q 2011/0058 Crossbar; Matrix
• CPC Class Codes: H04Q 2011/0083 Testing; Monitoring
• CPC Class Codes: H04Q 2011/0088 Signalling aspects

Abstract

Scalable and modular WDM systems to provide a number of processing functions which include, among others, signal detection, signal monitoring, wavelength conversion, signal regeneration, and generation of new WDM channels. Such WDM systems include a platform with an optical switching network and module slots for engaging WDM modules of different processing functions. Both protocol transparent and opaque WDM modules may be included in such a WDM system to provide versatile applications.

Claims

1. A system, comprising:

a support platform;

an optical switching network of a plurality of optical switches disposed on said platform to redirect one or more optical beams in response to control signals respectively applied to said optical switches;

a plurality of module slots located on said platform and distributed around said optical switching network, each module slot including an engaging mechanism to removably engage a module which either directs one or more optical beams to said optical switching network or receives one or more optical beams from said optical switching network;

an input fiber module having an input fiber port to receive a wavelength-division-multiplexed (“

WDM”

) signal formed of a plurality of optical carriers of different wavelengths, an array of output ports to output said optical carriers separately, and a WDM demultiplexer coupled between said input fiber port and said output ports to separate said optical carriers into said output ports, respectively, wherein said input fiber module is engaged to a first module slot on said platform to couple said optical carriers respectively output from said output ports to said optical switching network;

an output fiber module, engaged to a second module slot on said platform, having an array of input ports at least a portion of which respectively receive optical carriers of different wavelengths from said optical switching network, an output fiber port, and a WDM multiplexer coupled between said input ports and said output fiber port to combine said received optical carriers into an output WDM signal in said output fiber port;

a laser module engaged to a third module slot on said platform, having an array of lasers to produce laser beams at different wavelengths and arranged to direct said laser beams to different optical switches in said switching network; and

a wavelocker module on said platform and operable to detect frequency stability of each laser beam out of said laser module and to produce a laser control signal to each laser in said laser module to stabilize laser wavelength.

2. The system as in claim 1, wherein said wavelocker module is integrated with said laser module.

3. The system as in claim 1, wherein said wavellocker is separate from said laser module and is engaged to a fourth module slot on said platform which is located to allow said wavelocker module to receive said laser beams from said laser module through at least a portion of said optical switching network.

4. The system as in claim 1, further comprising a detector module engaged to a designated module slot on said platform and having an array of photosensors arranged to receive optical beams from different optical switches in said switching network and to produce detector output signals indicating information in said optical beams.

5. The system as in claim 1, further comprising an optical wavelength conversion module engaged to a designated module slot on said platform to receive a signal beam at a first WDM wavelength from said optical switching network and a conversion optical beam at a second WDM wavelength different from said first WDM wavelength, wherein said optical wavelength conversion module is responsive to a modulation in said signal beam to transfer information from said signal beam to said conversion optical beam.

6. The system as in claim 5, wherein said optical wavelength conversion module includes at least one semiconductor optical amplifier which exhibits an optical cross gain between said first and said second WDM wavelengths.

7. The system as in claim 5, wherein said optical wavelength conversion module includes at least one semiconductor optical amplifier which exhibits an optical cross phase modulation between said first and said second WDM wavelengths.

8. The system as in claim 1, further comprising an optical-to-electrical interface module engaged to a designated module slot on said platform to receive one or more optical beams from said optical switching network, said optical-to-electrical interface module operable to drive one laser in said laser module according to a received optical beam from said optical switching network.

9. The system as in claim 8, wherein said optical-to-electrical interface module drives said one laser to produce a new laser beam to carry information from said received optical beam at the same laser wavelength as said received optical beam.

10. The system as in claim 8, wherein said optical-to-electrical interface module drives said one laser to produce a new laser beam to carry information from said received optical beam at a laser wavelength different from a wavelength of said received optical beam.

11. A business method for providing optical switching systems to customers, comprising:

providing an optical switching network of a plurality of optical switches disposed on a platform to redirect one or more optical beams in response to control signals respectively applied to said optical switches;

constructing a plurality of module slots on said platform which are distributed around said optical switching network, each module slot including an engaging mechanism to removably engage a module to said platform and defining N optical positions to optically communicate with N optical switches in said switching network, respectively;

determining module types and designs according to a customer specification;

manufacturing the modules according to the designs;

installing the modules in respective module slots to complete a system;

testing operational performance of each module to determine whether all customer requirements are met; and

shipping the complete system to the customer.

12. The method as in claim 11, further comprising updating the system by modifying or replacing one or more modules.

13. The method as in claim 11, wherein said switching network includes a plurality of switching arrays each of which includes N optical switches at discrete positions along a diagonal line of a square or rectangle.

14. The method as in claim 11, wherein said switching network includes a number N of K×

K optical switches located on said platform, each having K input terminals and K output terminals and operable independently from another optical switch, to switch an input to any of said K output terminals and to switch different inputs to different outputs.

16. The method as in claim 15, wherein said optical processing includes using an optical semiconductor amplifier to optically amplify said second optical WDM channel to produce said new optical WDM channel by using energy from another optical beam at the same wavelength in said optical semiconductor amplifier.

17. The method as in claim 15, wherein said new optical WDM channel has a WDM wavelength different from a WDM wavelength of said second optical WDM channel.

15. A method, comprising:

directing a plurality of optical WDM channels to an optical switching network;

converting at least a first optical WDM channel of said optical WDM channels into an electronic signal to retrieve data according to a first data protocol in said first optical WDM channel; and

optically processing at least a second optical WDM channel of said optical WDM channels to produce a new optical WDM channel with information associated with information in said second optical WDM channel, without relying on a second data protocol in said second optical WDM channel and without converting said second optical WDM into an electronic signal.