ABSTRACT
Perhaps some of the most intriguing aspects of 3D integration technology are the new capabilities that could be brought to bear by bringing very dissimilar technologies into intimate contact. One interesting possibility is the integration of 3D photonic interconnects with multi-core processors, which have the potential to dramatically reduce the power of interconnects particularly in the regime where the interconnect distance is long, and the data rates are high. A conceptual 3D optical interconnect scheme is shown in Fig. 1.3.12 Here a complete network-on-a-chip is shown, which utilizes a bottom multi-core processor layer, an intermediate memory layer, and an optical interconnect layer on top. In such a system, local interconnects could be provided by standard metal wiring, whereas global connections would be made using a photonic interconnect fabric consisting of silicon waveguides. The interconnect power has been calculated for such a scheme and is found to be nearly 2 orders of magnitude lower compared to electrical interconnects.12 The photonic network provides the additional advantage that off-chip I/O is achieved at the same bandwidth with little additional power.
