Highly power-efficient (2 pJ/bit), 128Gbps 16QAM signal generation of coherent optical DAC transmitter using 28-nm CMOS driver and all-silicon segmented modulator

We demonstrated a highly power-efficient coherent optical digital-to-analog converter transmitter. 2pJ/bit operation was realized by combining an all-silicon segmented modulator and a CMOS inverter driver. The bit-error-rate was less than the 25.5% of SD-FEC limit. © 2022 The Author(s)

1. Introduction

Future communication systems require both larger transmission density and higher energy-efficiency than existing systems for optical transceivers. Silicon photonics technology is a promising platform that provides significant advantages in terms of its size, cost, and power consumption compared to conventional technologies. Although silicon photonics has already been developed as a commercial technology, further improvements are under investigation [1]. Recently, the Optical Internetworking Forum launched an 800G coherent project. The transmission capacity must be doubled while almost the maintaining form factors and the transmission distance; particularly, it is necessary to double the energy efficiency. From this viewpoint, improving the energy efficiency of the optical transmitter, such as an optical modulator driver and an electrical digital-to-analog converter (DAC), would be crucial in the future.