Very high speed data transfer networks will be required in the late 1990's to complement the development of distributed processors incorporating vhsic and gaas technologies. Fiber optic data bus technology can provide the wide band width communication media required with the additional benefits of invulnerability to emi/emp while being physically small, light, and strong. The proposed phase ii sbir is to design, breadboard, and demonstrate a very high speed, 500 mb/s, fiber optic data bus interface module, bim, with gaas encoding and decoding. In addition, a bus architecture will be developed for inserting the technology onto a platform to serve as a "master" bus for inter-systems or intra-platform data transfer. This bus would access systems through gateways ro other buses, through standard ntds (10 mb/s) interfaces, or directly to terminals such as sensors with 10-100 mb/s data rates.