Arbitrated optical network using tunable drop filters

• US 8,655,120 B2
• Filed: 07/11/2011
• Issued: 02/18/2014
• Est. Priority Date: 07/11/2011
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Koka, Pranay, McCracken, Michael O., Schwetman, Herbert D. Jr., Zheng, Xuexhe, Krishnamoorthy, Ashok V.
• Primary Examiner(s): Pak, Sung
• Application Number:
  US13/180,364
• Publication Number:
  US 20130016941A1
• Time in Patent Office: 953 Days
• Field of Search: None
• US Class Current: 385/14
• CPC Class Codes: G02B 2006/12061 Silicon
• CPC Class Codes: G02B 6/4215 the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections

Abstract

In a multi-chip module (MCM), integrated circuits are coupled by optical waveguides. These integrated circuits receive optical signals from a set of light sources which have fixed carrier wavelengths. Moreover, a given integrated circuit includes: a transmitter that modulates at least one of the optical signals when transmitting information to at least another of the integrated circuits; and a receiver that receives at least one modulated optical signal having one of the carrier wavelengths when receiving information from at least the other of the integrated circuits. Furthermore, the MCM includes tunable drop filters optically coupled to the optical waveguides and associated integrated circuits, wherein the tunable drop filters pass adjustable bands of wavelengths to receivers in the integrated circuits. Additionally, control logic in the MCM provides a control signal to the tunable drop filters to specify the adjustable bands of wavelengths.

Claims

1. A multi-chip module (MCM), comprising:

integrated circuits configured to receive optical signals from a set of light sources, which have fixed carrier wavelengths, wherein a given integrated circuit includes;

a transmitter configured to modulate at least one of the optical signals when transmitting information to at least another of the integrated circuits; and

a receiver configured to receive at least one modulated optical signal having one of the carrier wavelengths when receiving information from at least the other of the integrated circuits;

first optical waveguides, optically coupled to the integrated circuits, to convey modulated optical signals from transmitters in the integrated circuits;

second optical waveguides, optically coupled to the first optical waveguides, to convey the modulated optical signals;

tunable drop filters optically coupled to the second optical waveguides and associated integrated circuit, wherein the tunable drop filters are configured to pass adjustable bands of wavelengths to receivers in the integrated circuits, and wherein a given adjustable band of wavelengths of a given tunable drop filter associated with the given integrated circuit includes one of the carrier wavelengths; and

control logic configured to provide a control signal to the tunable drop filters to specify the adjustable bands of wavelengths, thereby defining routing of at least the one of the optical signals in the MCM during communication between at least a pair of the integrated circuits.

2. The MCM of claim 1, wherein the integrated circuits are arranged in an array;

wherein the first optical waveguides are optically coupled to rows in the array; and

wherein the second optical waveguides are optically coupled to columns in the array.

3. The MCM of claim 2, wherein the integrated circuits in a given column transmit modulated optical signals having the same carrier wavelength, while integrated circuits in a given row transmit modulated optical signals having different carrier wavelengths.

4. The MCM of claim 1, wherein the first optical waveguides and the second optical waveguides are implemented in different layers on a substrate;

and

wherein the MCM further includes interlayer couplers that optically couple the first optical waveguides and the second optical waveguides.

5. The MCM of claim 4, wherein the first optical waveguides and the second optical waveguides are implemented on the substrate using silicon-on-insulator technology.

6. The MCM of claim 1, wherein the control signal specifies a number of tunable drop filters associated with the given integrated circuit that have adjustable bands of wavelengths that include carrier wavelengths, thereby specifying a bandwidth during communication between at least the pair of the integrated circuits.

7. The MCM of claim 1, wherein communication between the pair of integrated circuits involves an arbitration technique so that only optical signals having a given carrier wavelength, which are communicated between the pair of integrated circuits, are conveyed on a given first optical waveguide and a given second optical waveguide at a given time.

8. A system, comprising:

a set of light sources configured to output optical signals having fixed carrier wavelengths;

integrated circuits optically coupled to the set of light sources, wherein a given integrated circuit includes;

a transmitter configured to modulate at least one of the optical signals when transmitting information to at least another of the integrated circuits; and

a receiver configured to receive at least one modulated optical signal having one of the carrier wavelengths when receiving information from at least the other of the integrated circuits;

first optical waveguides, optically coupled to the integrated circuits, to convey modulated optical signals from transmitters in the integrated circuits;

second optical waveguides, optically coupled to the first optical waveguides, to convey the modulated optical signals;

tunable drop filters optically coupled to the second optical waveguides and associated integrated circuit, wherein the tunable drop filters are configured to pass adjustable bands of wavelengths to receivers in the integrated circuits, and wherein a given adjustable band of wavelengths of a given tunable drop filter associated with the given integrated circuit includes one of the carrier wavelengths; and

control logic configured to provide a control signal to the tunable drop filters to specify the adjustable bands of wavelengths, thereby defining routing of at least the one of the optical signals in the system during communication between at least a pair of the integrated circuits.

9. The system of claim 8, wherein the integrated circuits are arranged in an array;

wherein the first optical waveguides are optically coupled to rows in the array; and

wherein the second optical waveguides are optically coupled to columns in the array.

10. The system of claim 9, wherein the integrated circuits in a given column transmit modulated optical signals having the same carrier wavelength, while integrated circuits in a given row transmit modulated optical signals having different carrier wavelengths.

11. The system of claim 8, wherein the first optical waveguides and the second optical waveguides are implemented in different layers on a substrate;

and

wherein the system further includes interlayer couplers that optically couple the first optical waveguides and the second optical waveguides.

12. The system of claim 11, wherein the first optical waveguides and the second optical waveguides are implemented on the substrate using silicon-on-insulator technology.

13. The system of claim 8, wherein the control signal specifies a number of tunable drop filters associated with the given integrated circuit that have adjustable bands of wavelengths that include carrier wavelengths, thereby specifying a bandwidth during communication between at least the pair of the integrated circuits.

14. The system of claim 8, wherein communication between the pair of integrated circuits involves an arbitration technique so that only optical signals having a given carrier wavelength, which are communicated between the pair of integrated circuits, are conveyed on a given first optical waveguide and a given second optical waveguide at a given time.

15. A method for routing optical signals in an MCM, the method comprising:

selecting a control signal based on desired communication between at least a pair of integrated circuits in the MCM, which are optically coupled by optical waveguides, wherein a given integrated circuit modulates at least one of optical signals having carrier wavelengths when transmitting information to at least another of the integrated circuits, and receives at least one modulated optical signal having one of the carrier wavelengths when receiving information from at least the other of the integrated circuits; and

providing the control signal to tunable drop filters optically coupled to the optical waveguides and associated integrated circuits, thereby specifying adjustable bands of wavelengths passed by the tunable drop filters and defining routing of at least the one of the optical signals in the MCM during communication between at least a pair of the integrated circuits,

wherein the tunable drop filters are configured to pass adjustable bands of wavelengths to receivers in the integrated circuits, and

wherein a given adjustable band of wavelengths of a given tunable drop filter includes one of the carrier wavelengths.

16. The method of claim 15, wherein communication between the pair of integrated circuits involves an arbitration technique so that only optical signals having a given carrier wavelength, which are communicated between the pair of integrated circuits, are conveyed on a given first optical waveguide and a given second optical waveguide at a given time.

17. The method of claim 15, wherein the integrated circuits are arranged in an array;

wherein first optical waveguides are optically coupled to rows in the array; and

wherein second optical waveguides are optically coupled to columns in the array.

18. The method of claim 17, wherein the integrated circuits in a given column transmit modulated optical signals having the same carrier wavelength, while integrated circuits in a given row transmit modulated optical signals having different carrier wavelengths.

19. The method of claim 17, wherein the first optical waveguides and the second optical waveguides are implemented in different layers on a substrate;

and

wherein interlayer couplers optically couple the first optical waveguides and the second optical waveguides.

20. The method of claim 15, wherein the control signal specifies a number of tunable drop filters associated with the given integrated circuit that have adjustable bands of wavelengths that include carrier wavelengths, thereby specifying a bandwidth during communication between at least the pair of the integrated circuits.