9318416 Cruz The principal investigators will use their expertise in the areas of communications networks, optical devices, fiber optics, and systems engineering in a cohesive research effort aimed at demonstrating the feasibility of time-based optical multiplexors. Time-based multiplexing is a fundamental operation that must be performed in large-scale wide- area networks. The research will examine architecture alternatives and demonstrate feasibility by building and testing scalable prototype multiplexors. A major difficulty in the design of multiplexors is dealing with contention. The conceptual prototype of a time-based optical multiplexor, in this study, is based on the detection of optical packets at the packet rate, as opposed to the detection of the optical data at the much higher data rate. For example, the optical packets can be detected by splitting off a small part of the optical signal using an optical-fiber directional coupler, with these signals detected by a high-sensitivity detector. For a two-to-one multiplexor, the packet detection will be used to configure a 2 x 2 guided-wave directional coupler switch. If only one input has a packet, the packet is routed to the output. If both inputs have packets, then one packet is routed to the output while the other packet is sent through an optical fiber delay line, and subsequently fed back into another switch. Several packet detectors and switches can be used to implement various scheduling algorithms, and to offer a higher degree of system reliability. The multiplexors will be developed using commercially available fiber optic and optoelectronic components. We will iteraltively examine architecture alternatives and refine our prototypes. This will maximize the interaction between the device and network researchers. ***
