Kaiam and Corning demonstrate co-packaged Photonic Interconnect for Terabit Chip Interconnect
By converting high-speed signals to optical within the switch package, CoPPhI could cut chip interconnect power consumption by half.
Kaiam Corp and Corning Inc. are showcasing an optical engine and single-mode fibre interface connector suitable for co-packaging with a 12.8 Tb/s switch chip (CoPPhI) at OFC March 2017. The optics are capable of 1.6Tb/s throughput from four fibres at 400Gbps per fibre (4λ x 100Gbps, readily extended to 8λ). The live demo interoperates at 25Gb/s per λ with a standard CWDM4 transceiver. Multiple CoPPhI engines can be co-packaged in close proximity to the four sides of a switch ASIC to support 12Tb/s+ of optical connectivity. Single-mode fibres are interfaced to the engine using a low-profile, precision connector compatible with electronic packaging and assembly processes including solder reflow.
By the 12.8Tb/s switch IC generation, the power required to drive signals over a PCB between the switch IC and the optical module will equal the power required for the switching function itself. By shrinking the optics and pushing the electrical-optical conversion point close to the switch IC, the required line drive power can be minimised. Broadcom's Rob Stone had issued a call for integrated optical chip interconnect to solve the looming power issue at 2014's Executive Forum, where he stated "co-packaging of optics could be useful when switch IC interface speeds are 50Gb/s/lane but may become necessary once the lane speeds are 100Gb/s per lane." (Note: 50Gb/s per lane chips are expected to be available from several vendors in 2017.)
"This is not just a nice-to-have; this will be a must-have a couple of Ethernet switch generations down the road. On-board optics such as COBO allow the industry to explore post-pluggable usage models but still require power-hungry electrical interfaces," said Rob Kalman, Kaiam's VP of Marketing. "We're working on the part of the problem that actually eliminates this power while also addressing the pressing cost and density needs of our hyperscale data centre customers."
"Thermal stability has been a challenge for fibre components subjected to the processing and operation ranges of electronics. Corning is developing novel solutions to provide single-mode stability for multi-fibre connectors in a form factor compatible with chip packages. This demonstration is an important milestone for the future of data centres and the role that optics will play," said David Hubbard, Vice President and Business Manager OEM, Corning Optical Communications.
