Wavelength-division multiplexing for use in multi-chip systems

1. A system, comprising:

an array of chip modules (CMs) that includes N subsets of CMs, each of which includes M CMs, wherein a given CM in the array includes a semiconductor die that is configured to communicate data signals with one or more adjacent CMs through electromagnetic communication using proximity connectors;

wherein the proximity connectors are coupled to a surface of the semiconductor die;

wherein the given CM is configured to communicate optical signals with other CMs through an optical signal path using optical communication, wherein the given CM is coupled to CMs in a given subset by a first optical signal path and is coupled to other subsets by a second optical signal path, and wherein the optical signal paths are configured for bidirectional communication of information between the CMs;

wherein the optical signals are encoded using wavelength-division multiplexing (WDM),

wherein CMs in the array communicate with the given CM using optical signals in a sub-channel on the first optical signal path or on the second optical signal path that is associated with a given wavelength in a set of wavelengths, and wherein communicating with the given CM using the optical signals in the sub-channel comprises removing optical signals having the given wavelength from the optical signal path for the sub-channel without removing other optical signals from the optical signal path for the sub-channel.

2. The system of claim 1 , wherein the optical communication between CMs includes communication of optical signals between two CMs that pass through an intermediate CM without intermediate processing of electrical signals associated with the optical signals.

3. The system of claim 1 , wherein the electromagnetically coupled communication includes capacitive communication, inductive communication, conductive communication, or optical communication.

4. The system of claim 1 , wherein the connectors include optical coupling elements.

5. The system of claim 4 , wherein optical coupling elements include a lens, a diffraction grating, an arrayed-waveguide gating, or a mirror.

6. The system of claim 1 , wherein the optical proximity communication includes evanescent coupling.

7. The system of claim 1 , wherein the array includes a 1-dimensional chain of CMs or a 2-dimensional array of CMs.

8. The system of claim 1 , wherein the optical signal path facilitates communication in a first direction and a second optical signal path facilitates communication in a second direction.

9. The system of claim 8 , wherein the first direction and the second direction are perpendicular to each other.

10. The system of claim 8 , wherein the first direction and the second direction are parallel to each other but oriented in opposite directions.

11. The system of claim 1 , wherein the optical signal path includes one or more waveguides.

12. The system of claim 1 , wherein the array includes N subsets of CMs, and wherein the given CM communicates with CMs in a given subset using optical signals in a sub-channel on the optical signal path, which is associated with a given wavelength in a set of N wavelengths.

13. The system of claim 1 ,

wherein within the given subset CMs communicate with the given CM using optical signals on a sub-channel in the first optical signal path, which is associated with a given wavelength in a set of M wavelengths; and

wherein the given CM communicates with another subset using optical signals in another sub-channel on the second optical signal path, which is associated with a given wavelength in a set of N wavelengths.

14. The system of claim 1 , wherein the set of wavelengths includes N×M wavelengths.

15. The system of claim 1 ,

wherein CMs within a given subset are coupled by a separate optical signal path;

wherein the given CM communicates with a particular CM in the given subset using optical signals in a sub-channel on the separate optical signal path, which is associated with a given wavelength in a set of M wavelengths.

16. The system of claim 1 , wherein a surface of a first CM in the array faces a surface of a second CM in the array, so that connectors on the first CM are coupled to connectors on the second CM, thereby facilitating the electromagnetic communication between the first CM and the second CM.

17. The system of claim 1 , wherein proximity connectors on a first CM in the array are coupled to connectors on a second CM in the array via a bridge component, thereby facilitating the electromagnetic communication between the first CM and the second CM.

18. A method for communicating data signals in an array of CMs that includes N subsets of CMs, each of which includes M CMs, the method comprising:

receiving optical signals from a first CM at a second CM via an optical signal path and receiving the optical signals from the second CM at a third CM via the optical signal path, wherein the optical signal path is configured for bidirectional communication of information between the CMs.

wherein adjacent CMs, such as the first CM and the second CM or the second CM and the third CM, are configured to communicate with each other using electromagnetic communication through electromagnetically coupled connectors;

wherein the optical signals are encoded using wavelength-division multiplexing (WDM);

wherein the given CM which can include the first or second or third CM is coupled to CMs in a given subset by a first optical signal path and is coupled to other subsets by a second optical signal path;

wherein CMs in the array communicate with the given CM using optical signals in a sub-channel on the first optical signal path or on the second optical signal path, which is associated with a given wavelength in a set of wavelengths, and wherein communicating with the given CM using the optical signals in the sub-channel comprises removing optical signals having the given wavelength from the optical signal path for the sub-channel without removing other optical signals from the optical signal path for the sub-channel.

19. A computer system, comprising:

a processor;

a memory;

an array of chip modules (CMs) that includes N subsets of CMs, each of which includes M CMs, wherein a given CM in the array includes a semiconductor die that is configured to communicate data signals with one or more adjacent CMs through electromagnetic communication using connectors;

wherein the proximity connectors are coupled to a surface of the semiconductor die;

wherein the given CM is configured to communicate optical signals with other CMs through an optical signal path using optical communication, wherein the given CM is coupled to CMs in a given subset by a first optical signal path and is coupled to other subsets by a second optical signal path, and wherein the optical signal paths are configured for bidirectional communication of information between the CMs;

wherein the optical signals are encoded using wavelength-division multiplexing (WDM),

wherein CMs in the array communicate with the given CM using optical signals in a sub-channel on the first optical signal path or on the second optical signal path, which is associated with a given wavelength in a set of wavelengths, and wherein communicating with the given CM using the optical signals in the sub-channel comprises removing optical signals having the given wavelength from the optical signal path for the sub-channel without removing other optical signals from the optical signal path for the sub-channel.

20. The system of claim 1 , wherein communicating optical signals with other CMs through an optical signal path using optical communication comprises communicating clock signals for the array of CMs.