Simplified Transceivers for Short-Reach Coherent-Lite Systems

While coherent transceivers are widely deployed for long-haul transmissions, short-reach systems predominantly rely on intensity modulation with direct detection. In this paper, we discuss the promise coherent-lite systems offer for short-reach applications. These systems represent a simplified version of conventional coherent systems, being simplified to lower cost and improve power efficiency while maintaining high performance. We review various digital and photonic solutions for designing coherent-lite systems for both data center networks and access networks, addressing future data rate requirements beyond 800 Gbit/s for data center interconnects and 200 Gbit/s for passive optical networks.