An important issue in the design of interconnection networks for massively parallel computers is scalability. Size-scalability refers to the property that the number of nodes in the network can be increased with negligible effect on the existing configuration and generation-scalability implies that the communication capabilities of a network should be large enough to support the evolution of processing elements through generations. The lack of size-scalability has limited the use of certain types of interconnection networks (e.g., hypercube) in the area of massively parallel computing. This paper presents a new optical interconnection network, called an Optical Multi-Mesh Hypercube (OMMH), which is both size- and generation-scalable while combining positive features of both the hypercube (small diameter, high connectivity, symmetry, simple routing, and fault tolerance) and the mesh (constant node degree and scalability) networks. Also presented is a three-dimensional optical implementation methodology of the OMMH network.