Optimizing Optical Engine Features for Subsea Cable Systems

We introduce a taxonomy for subsea optical fiber cables as used for intercontinental telecommunications systems. With reference to this new classification, we describe how the design of optical engines has both influenced, and been influenced by, the development of subsea cables. We outline the pivotal role coherent transceivers have played in the development of high-capacity subsea cables, specifically with reference to advances in digital signal processing and coded modulation, and we highlight the opportunities and challenges of upgrading legacy systems with state-of-the-art coherent transceivers. In this work, we also look to future cable designs and ask how the availability of fundamentally new fiber types (specifically multicore and hollow core fibers) will have an influence on subsea cables and, once again, change transceiver requirements.