Hideyuki Nosaka

High-performance compound-semiconductor integrated circuits for advanced digital coherent optical communications systems

Communications traffic over photonic networks is exponentially increasing due to the spread of broadband applications. To cope with the rapid growth, novel 100-Gb/s digital coherent systems have been deployed recently in optical core networks. Further research and development of digital coherent technologies with channel rates of beyond 100Gb/s is now being conducted. Optical transceivers for such high-speed communications systems need high-performance analog and mixed-signal electronic circuits such as optical modulator drivers, transimpedance amplifiers (TIAs), analog-to-digital converters (ADCs), and digital-to-analog converters (DACs). Compound-semiconductor integrated circuits (ICs) have played key roles in this technical field. This paper reviews recent trends in compound-semiconductor ICs for such advanced digital coherent optical communications systems and presents our latest results based on InP heterojunction bipolar transistor (HBT) technology.