|
A VCSEL is a key component in hyper-scale datacenter and supercomputer networks because of its fascinating properties, which provides high-speed operations, low power consumption, small footprint, wafer-scale testing, low-cost packaging, ease of fabrication into arrays. A VCSEL is the most popular choice for use in optical interconnection of datacenters and supercomputers. High speed operations at data rates beyond 50 Gbps were demonstrated through the optimization of epi-wafers and device structures, and reached at over 70 Gbps with electrical equalization employed. But there still remain challenges in increasing the modulation speed, which is mainly limited by the relaxation oscillation frequency and parasitics. An effective approach was proposed and demonstrated using a coupled cavity structure functioning like optical equalization. In particular, a VCSEL solution gives us high-speed and low-power consumption, which will meet requirements in datacenter networks. We developed a single-mode 1060nm metal-aperture VCSELs, which offers high-density I/O platform with low power consumption below 50fJ/bit and also could extend a fiber link length over 10 km. In addition, co-packaged optics (CPO) has been attracting much attention in datacenter and edge computing networks since CPO brings optics much closer to switch ASICs in a single package, so that power consumption could be saved by reducing the reach. It is critical that CPO solutions deliver substantial benefits in terms of energy efficiency and module density over exiting pluggable optics. We started the NICT project toward high-speed and low-power consumption CPO transceivers based on VCSEL array and multi-core fiber (MCF), which could deliver advantages on power consumptions and capacity density per module. In this paper, we present our recent activity on high-speed transverse-coupled-cavity VCSELs and their array for datacenter networks.
|
