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

Abstract

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.

Optimization of the coupling efficiency under self-injection locking in a narrow linewidth hybrid wavelength tunable laser diode

“…Fields such as digital coherent optical communication [1][2][3][4][5] and light detection and ranging (LiDAR) [6][7][8][9][10][11] have recently developed owing to an increase in the amount of information and the trend toward the automated driving of automobiles. These fields have increased the demand for semiconductor lasers that are characterized by low power consumption, low cost, and small size.…”

Digital Inverse Multiplexing for Transmitters With Symbol Rates Over DAC Bandwidth Limit

“…Most commercial coherent transceivers employ complementary metal-oxide semiconductor (CMOS) DACs co-integrated with CMOS digital signal processing (DSP) application-specific integrated circuits (ASICs), and efforts to increase the BW of CMOS DAC are ongoing [15,16]. In addition, DACs based on silicon germanium (SiGe) Bipolar CMOS (BiCMOS) [3,4] and indium phosphide (InP) [23] technologies in conjunction with baseband interleaving techniques are also actively researched and hold the promise of higher BW, although we emphasize that the co-integrability advantage of CMOS DACs with DSP ASICs is so important that it has been making the CMOS DACs the primary choice for commercial transceivers.…”