Co-packaged optics: optical infrastructure from the faceplate to the PIC

Abstract

Co-Packaged Optics is a technology development expected to be widely deployed within the next few years, to support continued increases in bandwidth for data centers and HPC while energy per bit is driven down. CPO architectures replace transceivers in faceplate pluggable modules with an optical link from the faceplate to transceiver PICs packaged on or near the ASIC switch substrate. The optical connections to the PIC and on the faceplate are the subjects of a lot of attention, with multiple approaches under consideration for the former and existing or imminent solutions for the latter. The intervening optical fibers and cables have however been relatively neglected, but the careful engineering of these components is also critical. This paper will review the status of the development for near-term implementation of the optical infrastructure from the faceplate to the PIC, with particular focus on the required optical and mechanical properties of optical fiber and its deployment in the switch box. We will also discuss how future developments in this infrastructure can help sustain continued bandwidth increases and reduction in power consumption.