Free-space holographic optical interconnects for board-to-board and chip-to-chip interconnections.

We describe a free-space holographic optical interconnect system designed for signal communication between chips and circuit boards on a common backplane. The system uses a transparent optical substrate-mode holograms to implement chip-to-chip interconnections and free space for board-to-board interconnections. Realization of a variety of interconnect functions with substrate-mode holograms is described. A three-board holographic interconnect system is also experimentally demonstrated.