Access Networks Based on Tunable Lasers

State-of-the-art, prospects, and challenges of next-generation optical access technology based on tunable lasers are discussed. These considerations can also be applied to various backhaul and mobile fronthaul applications since these have similar characteristics and requirements, and have to share at least part of the optical distribution networks. Potential advantages of tunable lasers over competing approaches (e.g., seeded reflective transmitters) include higher bit-rate × reach products and better tolerance to reflections in the fiber plant. Today, the main issue is still the lack of available low-cost tunables with sufficient tuning range and launch power. However, significant progress has been made in the last few years to bring such lasers closer to commercialization. In this paper, we will review low-cost tunable laser approaches and report on latest technical results. We will also give an overview on current standardization activities and give an outlook on next-generation optical access, backhaul and fronthaul networks which also support active-site consolidation.