Recent advances on chip-to-chip optical interconnect

Copper (Cu) interconnect has been used for communication systems at shorter length scales for both latency and bandwidth sensitive applications. However, as the computational bandwidth of the integrated circuits increases dramatically, Cu interconnect at short distances especially in bandwidth sensitive applications is struggling to keep up. This presents a good opportunity for optical interconnect to penetrate the short distance world. This paper reviews the latest advances of optical interconnect for off-chip high bandwidth communications. The focus will be on the materials and processing aspects for realizing optical interconnects through low cost and manufacturable approaches, especially on various novel schemes to achieve passive optical alignment between optical device and waveguide, and on novel package architectures to achieve high bandwidth using the optical interconnects.