Splitterless optical broadcast switch

• US 5,870,216 A
• Filed: 04/09/1997
• Issued: 02/09/1999
• Est. Priority Date: 10/26/1995
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Rollins, David L., Brock, John C., Lembo, Lawrence J.
• Primary Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US08/826,957
• Time in Patent Office: 671 Days
• Field of Search: 359/172, 359/133, 359/130, 359/128, 359/117, 455/12.1
• US Class Current: 398/49
• CPC Class Codes: H04B 10/801 using optical interconnects, e.g. light coupled isolators, circuit board interconnections
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04Q 11/0001 using optical switching
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)

Abstract

A splitterless optical broadcast switch (110) for routing a plurality of optical carrier signals. The splitterless optical broadcast switch (110) includes an optical source (112) for generating a plurality of unmodulated optical carrier signals. A first stage routing module (114) routes the plurality of unmodulated optical carrier signals. A modulating module (116) receives a plurality of RF input signals and modulates each of the RF input signals onto any number of the unmodulated optical carrier signals to generate a plurality of modulated optical carrier signals. A second stage routing module (118) routes the plurality of modulated optical carrier signals complimentary to the first stage routing module (114). An output module (120) receives the plurality of modulated optical carrier signals such that the optical output from the optical source (112) is paired to a complimentary optical input of the output module (120).

Claims

1. A splitterless optical broadcast switch for routing a plurality of optical carrier signals, said splitterless optical broadcast switch comprising:

an optical source operable to generate a plurality of unmodulated optical carrier signals;

a first stage routing module optically coupled to said optical source, said first stage routing module operable to route said plurality of unmodulated optical carrier signals;

a modulating module optically coupled to said first stage routing module, said modulating module operable to receive a plurality of RF input signals and operable to modulate each of said RF input signals received onto any number of said unmodulated optical carrier signals to generate a plurality of modulated optical carrier signals;

a second stage routing module optically coupled to said modulating module, said second stage routing module operable to route said plurality of modulated optical carrier signals complimentary to said first stage routing module; and

an output module operable to receive said plurality of modulated optical carrier signals, wherein each optical output from said optical source is paired to a complimentary optical input of said output module.

2. The splitterless optical broadcast switch as defined in claim 1 wherein said optical source includes a plurality of lasers and said output module includes a plurality of photodetectors, wherein each of said lasers is paired with one of said photodetectors.

3. The splitterless optical broadcast switch as defined in claim 1 wherein said modulating module includes a plurality of modulators, each of said modulators operable to simultaneously modulate any number of unmodulated optical carrier signals.

4. The splitterless optical broadcast switch as defined in claim 1 wherein said first stage routing module includes a first arrayed waveguide grating and said second stage routing module includes a second arrayed waveguide grating, wherein said second arrayed waveguide grating routes optical carrier signals complimentary to said first arrayed waveguide grating.

5. The splitterless optical broadcast switch as defined in claim 1 wherein said first stage routing module includes a plurality of spatial switches and a plurality of waveguide division multiplexers and said second stage routing module includes a plurality of wavelength division multiplexers and a plurality of spatial switches.

6. The splitterless optical broadcast switch as defined in claim 1 wherein said first stage routing module includes a plurality of spatial switches and a plurality of arrayed waveguide gratings and said second stage routing module includes a plurality of arrayed waveguide gratings and a plurality of spatial switches.

7. A splitterless optical broadcast switch for routing a plurality of optical carrier signals, said splitterless optical broadcast switch comprising:

a plurality of lasers, each of said lasers operable to generate an unmodulated optical carrier signal;

a first stage routing module optically coupled to said plurality of lasers, said first stage routing module operable to route each unmodulated optical carrier signal generated by said plurality of lasers;

a plurality of modulators, each of said modulators optically coupled to said first stage routing module and coupled to an RF input, each of said modulators operable to modulate each unmodulated optical carrier signal routed to it by said first stage routing module with an RF input signal to generate a plurality of modulated optical carrier signals;

a second stage routing module optically coupled to said plurality of modulators, said second stage routing module operable to route each of said modulated optical carrier signals generated by said plurality of modulators; and

a plurality of photodetectors, each of said photodetectors optically coupled to said second stage routing module, each of said photodetectors operable to receive a modulated optical carrier signal routed to it from said second stage routing module, wherein each of said photodetectors is paired with one of said lasers to receive said optical carrier signal from said laser.

8. The splitterless optical broadcast switch as defined in claim 7 wherein each of said modulators is operable to simultaneously modulate multiple unmodulated optical carrier signals routed to it by said first stage routing module with an RF input signal.

9. The splitterless optical broadcast switch as defined in claim 7 wherein each of said lasers is a tunable laser operable to be tuned to generate a plurality of unmodulated optical carrier signals each having a different wavelength.

10. The splitterless optical broadcast switch as defined in claim 7 wherein each of said photodetectors paired with one of said lasers includes a first optical coupler, an optical phase lock loop and a second optical coupler which are operable to provide coherent detection.

11. A splitterless optical broadcast switch for routing a plurality of optical carrier signals, said splitterless optical broadcast switch comprising:

optical means for generating a plurality of unmodulated optical carrier signals;

first stage routing means for routing said plurality of unmodulated optical carrier signals;

modulating means for receiving a plurality of RF input signals and for modulating each of said RF input signals with any number of said unmodulated optical carrier signals to generate a plurality of modulated optical carrier signals;

second stage routing means for routing said plurality of modulated optical carrier signals complimentary to said first stage routing means; and

output means for receiving said plurality of modulated optical carrier signals, wherein said output means is paired with said optical means.

12. The splitterless optical broadcast switch as defined in claim 11 wherein said optical means includes a plurality of lasers and said output means includes a plurality of photodetectors, wherein each of said lasers is paired with one of said photodetectors.

13. The splitterless optical broadcast switch as defined in claim 11 wherein said modulator means includes a plurality of modulators, each of said modulators operable to simultaneously modulate multiple unmodulated optical carrier signals with an RF input signal.

14. The splitterless optical broadcast switch as defined in claim 11 wherein said first stage routing means includes an N×

N array waveguide grating and said second stage routing means includes an N×

N array waveguide grating.

15. The splitterless optical broadcast switch as defined in claim 11 wherein said first stage routing means includes a plurality of spatial switches and said second stage routing means includes a plurality of spatial switches.

16. A splitterless optical broadcast switch for routing a plurality of optical carrier signals, said splitterless optical broadcast switch comprising:

a plurality of lasers, each of said lasers paired with a photodetector, each of said photodetectors operable to receive an optical carrier signal generated by said laser paired with said photodetector;

a plurality of modulators, each of said modulators operable to simultaneously modulate multiple optical carrier signals with an RF input signal;

a first stage routing module operable to route each of said optical carrier signals generated by said plurality of lasers to any of said plurality of modulators; and

a second stage routing module operable to route each of said optical carrier signals modulated by said plurality of modulators.

17. The splitterless optical broadcast switch as defined in claim 16 wherein said splitterless optical broadcast switch is employed in a communication and data handling satellite.

18. The splitterless optical broadcast switch as defined in claim 16 wherein the routing of said second stage routing module is complimentary to the routing of said first stage routing module.

19. The splitterless optical broadcast switch as defined in claim 16 wherein a subset of said plurality of modulators is paired with a first stage arrayed waveguide grating in said first stage routing module and a second arrayed waveguide grating in said second stage routing module.

20. A method for routing an optical carrier signal in a splitterless optical broadcast switch, said method comprising the steps of:

generating a first optical carrier signal;

routing said first optical carrier signal from a first input in a first stage routing module to any of a plurality of optical modulators;

modulating said first optical carrier signal with an RF input signal using one of said optical modulators; and

routing said first optical carrier signal modulated with said RF input signal in a second stage routing module to a first output complimentary to said first input of said first stage routing module.

21. The method as defined in claim 20 further comprising the steps of:

generating a second optical carrier signal;

routing said second optical carrier signal from a second input in said first stage routing module to any of said plurality of optical modulators;

simultaneously modulating said first optical carrier signal and said second optical carrier signal with an RF input signal using one of said optical modulators; and

routing said first optical carrier signal modulated with said RF input signal in said second stage routing module to said first output complimentary to said first input of said first stage routing module and routing said second optical carrier signal modulated with said RF input signal in said second stage routing module to a second output complimentary to said second input of said first stage routing module.