Optical interconnects have drawn recent interest in the setting of intra-chip or module communication. These systems typically employ an external laser to supply unmodulated light and information is generated and consumed within the chip or module using microring resonators that act as electrically controllable switches for an optical waveguide. The talk with use an abstract model of this setting to explore distributed mutual exclusion.

An optical architecture is described that distributes a token (shared resource) mutually exclusively among a set of nodes (processing elements). The token is granted in constant amortized time following a request, assuming constant propagation time for light within the chip. The architecture is distributed in the sense that nodes seeking the token initiate and terminate token requests independently without centralized control. It is asynchronous in that a node's request for and release of the token are completely independent of those of other nodes. Additionally, the distribution of tokens is fair, ensuring that no token request is denied more than n-1 times in succession, where n is the number of nodes in the system.