Optical cross-connect switch for high-bit-rate space-based communications

• US 20030138189A1
• Filed: 01/22/2002
• Published: 07/24/2003
• Est. Priority Date: 01/22/2002
• Status: Abandoned Application

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Strodtbeck, Andrew L., McKay, Anthony L., Rockwell, D. A.
• Application Number:
  US10/054,581
• Publication Number:
  US 20030138189A1
• Time in Patent Office: Days
• US Class Current: 385/15
• CPC Class Codes: G02B 6/2861 using fibre optic delay lines and optical elements associated with them, e.g. for use in signal processing, e.g. filtering delay lines in general H03H, H01P9/00; optical computing devices G06E
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• CPC Class Codes: G02B 6/3598 Switching means directly located between an optoelectronic element and waveguides, including direct displacement of either the element or the waveguide, e.g. optical pulse generation based on changing the optical properties of the medium G02F1/00; optical pulse generation in optical transmitters H04B10/508; optical pulse generation by controlling laser operation H01S3/00
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0018 using tunable transmitters or receivers
• CPC Class Codes: H04Q 2011/002 using optical delay lines or optical buffers or optical recirculation
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0039 Electrical control
• CPC Class Codes: H04Q 2011/0049 Crosstalk reduction; Noise; Power budget
• CPC Class Codes: H04Q 2011/006 Full mesh

Abstract

A router circuit has an electrical-to-optical converter for changing the plurality of electrical input signals into a plurality of optical input signals. A mixing circuit is coupled to the electrical-to-optical converter. The mixing circuit generates a plurality of substantially identical composite signals corresponding to the plurality of optical inputs. The composite signals comprise at least a portion of each of the plurality of optical signals. A plurality of optical bandpass filters is coupled, respectively, to each of said plurality of composite signals. The bandpass filters pass a portion of the composite optical signals to form a plurality of filtered signals. An optical-to-electrical converter is coupled to the plurality of bandpass filters. The optical-to-electrical converter converts the plurality of filtered optical signals into a respective plurality of electrical output signals.

Claims

1. A router circuit having a plurality of electrical input signals comprising:

an electrical-to-optical converter for changing the plurality of electrical input signals into a plurality of optical input signals;

a mixing circuit coupled to the electrical-to-optical converter, said mixing circuit generating a plurality of substantially identical composite signals corresponding to the plurality of optical inputs, said composite signals comprising at least a portion of each of said plurality of optical signals;

a plurality of optical bandpass filters coupled, respectively, to each one of said plurality of composite signals, said plurality of bandpass filters passing a portion of said optical signal to form a plurality of filtered signals, and

an optical-to-electrical converter circuit coupled to the plurality of bandpass filters, said optical-to-electrical converter converting said plurality of filtered optical signals into a plurality of respective electrical output signals.

2. A router circuit as recited in claim 1 wherein said plurality of bandpass filters comprises a respective plurality of center wavelengths.

3. A router circuit as recited in claim 2 further comprising a control circuit coupled to said electrical-to-optical converter, wherein said electrical-to-optical converter comprises a plurality of electrical-to-optical converters, said control circuit selecting a respective plurality of electrical-to-optical converter wavelengths in response to said plurality of bandpass center wavelengths.

4. A router circuit as recited in claim 3 wherein said plurality of wavelengths of the electrical-to-optical converter is tunable.

5. A router circuit as recited in claim 2 wherein said plurality of center wavelengths of the plurality of bandpass filters is tunable.

6. A router circuit as recited in claim 1 wherein said electrical-to-optical converter comprises a plurality of electrical-to-optical converters.

7. A router circuit as recited in claim 1 wherein said mixing circuit comprises at least a first plurality of mixers cross coupled with a second plurality of mixers.

8. A router circuit as recited in claim 1 wherein said electrical-to-optical converter comprises a modulated tunable laser having a programmed wavelength.

9. A router circuit as recited in claim 8 wherein said tunable laser is coupled to a control circuit and a temperature sensor, said control circuit tuning said laser in response to said temperature sensor to maintain the programmed wavelength.

10. A router circuit as recited in claim 1 further comprising a clock circuit, said clock circuit comprising a clock electrical-to-optical converter, an optical delay line and an optical-to-electrical converter.

11. A router circuit as recited in claim 10 wherein said optical delay line comprises an optical fiber.

12. A router circuit as recited in claim 1 wherein said optical-to-electrical converter comprises a photodiode.

13. A router circuit as recited in claim 1 wherein said mixing circuit comprises a passive star power splitter.

14. A satellite system comprising:

said electrical inputs comprising RF inputs;

a router circuit as recited in claim 1.

15. A satellite system as recited in claim 14 further comprising a buffer circuit receiving said plurality of RF signals, said buffer circuit synchronizing said electrical input signals within a predetermined tolerance before the router

16. A router circuit comprising:

an electrical-to-optical converter changing electrical inputs into optical signals;

a first mixing circuit coupled to a first group of said plurality of optical signals, said first mixing circuit having a first output and a second output, said first output and second output each having a first composite signal comprising said first group of optical signals;

a second mixing circuit coupled to a second group of said plurality of optical signals, said second mixing circuit having a third output and a fourth output, said third output and fourth output each having a second composite signal comprising said second group of optical signals;

a third mixing circuit coupled to said first and third outputs, said third mixing circuit generating a third composite signal comprising said first composite signal and said second composite signal;

a fourth mixing circuit coupled to said second output and fourth output, said fourth mixing circuit generating a fourth composite signal comprising said first composite signal and said second composite signal;

a bandpass filter circuit coupled to said third mixing circuit and said fourth mixing circuit, said bandpass filter circuit comprising a first and a second optical bandpass filter, said first bandpass filter coupled to said third composite signal for generating a first optical output and a second bandpass filter coupled to said fourth composite signal for generating a second optical output; and

an optical-to-electrical converter circuit coupled to said bandpass filter circuit for converting said first optical output to a first electrical output and said second optical output to a second electrical output.

17. A router circuit as recited in claim 16 wherein said electrical-to-optical converter comprises a modulated tunable laser.

18. A router circuit as recited in claim 17 wherein said tunable laser is coupled to a control circuit and a temperature sensor, said control circuit controlling said laser in response to a desired router operation and said temperature sensor

19. A router circuit as recited in claim 16 further comprising a clock circuit, said clock circuit comprising a clock electrical-to-optical converter, an optical time delay circuit and an optical-to-electrical converter.

20. A router circuit as recited in claim 16 wherein said optical-to-electrical converter comprises a photodiode.

21. A router circuit as recited in claim 16 wherein said first mixing circuit and said second mixing circuit comprise a respective first star power splitter and a second star power splitter.

22. A method of operating a routing circuit comprising:

converting a plurality of electrical signals to a respective plurality of modulated optical signals;

coupling the plurality of modulated optical signals to a cross connect switch;

forming a plurality of composite signals at a plurality of outputs of the cross-connect switch, said plurality of composite signals composed of said modulated optical signals;

converting each of the composite signals into an electrical output signal corresponding to a portion of said modulated optical signals.

23. A method as recited in claim 22 further comprising synchronizing the output signal using a clock signal.

24. A method as recited in claim 22 wherein synchronizing comprises delaying the clock signal an amount corresponding to a delay of the cross-connect switch, to obtain a delayed clock signal.

25. A method as recited in claim 22 wherein converting a plurality of electrical signals to a respective plurality of modulated optical signals comprises modulating a respective plurality of diode lasers, each of which is tuned to the center wavelength of a bandpass filter.