Multi-scale free-space optical interconnects for intrachip global communication.

摘要

This dissertation describes the design, analysis and experimental validation of new concepts addressing the escalating issues facing metal wires for intrachip global communication. The wires between the most remotely separated microchip regions, called global wires, are disproportionately problematic to implement and are predicted to fall short of the requirements for communication capacity in future microchip technologies. System-level interconnect modeling based on wire-length estimation shows that, even though they represent a very small percentage of the total wires on the chip, global wires consume excessive chip area and dissipate excessive power, due to the number of required repeaters, and significantly increase routing complexity due to via blockages. These trends herald the global interconnection-limited performance saturation of Moore's Law for microchips. Therefore, global wires are selected as candidates for replacement by optical interconnects. Three multi-scale optical systems are discussed to show the performance, misalignment tolerance, and functionality enhancement that can be gained by the synergistic combination of optics of multiple scales. Multi-scale optical design is then applied to intrachip interconnects to meet the configuration flexibility and global bandwidth capacity requirements of future microchips. The multi-scale free-space optical interconnection system designed, analyzed and experimentally validated in this work is tailored to meet the density and configuration flexibility requirements of future microchip generations. The use of multiple optical scales is shown to enhance performance, misalignment tolerance and functionality over the use of a single optical scale. Finally, a three-terminal optical device structure is proposed and discussed, to address the requirements of a low-power and high-density source for such a system.