The Consortium for On-Board Optics (COBO) has released Coherent COBO; CohOBO Applications, an application note that describes how COBO-specified technology can support coherent data center interconnect (DCI) applications.
The application note covers coherent COBO (CohOBO) module design considerations, management interface, and other aspects of leveraging coherent onboard optics in 400-Gbps and greater DCI system designs. COBO announced the first release of its specification set at OFC 2018 (see “COBO offers Release 1.0 specifications for onboard optical modules”).
The specification developers looked at both coherent and non-coherent applications, which the new application note focused on the former. The publication focuses on Class C modules that accommodate the necessary optical engines, digital signal processing (DSP) components, and power-density a coherent-based onboard optics implementation would require.
The COBO coherent specifications were created with optimized airflow and low power dissipation in mind, helping to enable placement of optics close to switch silicon. “The DCI application is taking off as data center operators split their workloads among multiple data centers to keep up with growing demand for data,” said CohOBO Working Group Chair Hugues Tournier of Ciena. “The use of COBO standard for coherent optical communications enables DCI technology to use the same footprint as short-reach optics.”