2016 Volume 13 Issue 18 Pages 20162003
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 100 Gb/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.