Silicon-based optical links using novel direct detection, coherent detection and dual polarization methods for new generation transport architectures

Providing a low-cost, reliable and end-to-end quality of service (QoS) guaranteed connectivity is going to be a major challenge in optical transport due to the immense growth in number of connected devices and traffic volume triggered by fifth-generation mobile networks (5G) and cloud networks. First, we discuss the architectures of the 5G transport network and the data center network, to capture the full value of connectivity. The paper offers an overview of the network requirements and how the integrated photonic platforms, along with the advanced modulation formats, play a key role to support the unprecedented requirements of 5G and massive cloud deployment. Second, we provide an overview of the recent work on the development of high-speed silicon photonic (SiPh) modulators to generate and transport PAM-4 signals. Third, recent advancements of the photodetectors, optical hybrids, and integrated coherent receivers on the silicon-on-insulator (SOI) platform are also described. The results suggest that, in the first access and aggregation segments of the network, integrated silicon-based modulators aided by PAM-4 modulation formats can support the stringent requirements of new generation transport networks in terms of speed, footprint and power consumption.