Design and performance of a multiprocessor system employing board-to-board free-space optical interconnections: COSINE-1

A practical thirty-six processor computer system employing manually reconfigurable board-to-board free-space optical interconnections has been built. The free-space optical interconnection section employs collimated beams that have 90 cm of transmission length at the maximum. It acts as a reconfigurable optical backplane that accommodates 144 input/output ports. The processors applied to the system are Transputers, each of which has four bidirectional links to communicate with other Transputers. This paper describes the design concept and the optical interconnection performances of the optical interconnection section employed in the constructed system.