Microcomb and Micro-Ring Modulator Driven DWDM Optical Transmitter With Ultra-High Speed of 20 × 128 Gb/s

High-speed and energy-efficient data center interconnects yearn for the high-performance optical interconnects, which are powered by the dense-wavelengthdivision-multiplexing (DWDM) optical transmitters with integrated multi-channel silicon modulators. However, the contradiction for minimizing the crosstalk while maximizing the transmission capacity remains a critical obstacle for optical transmitters. Here, we propose and demonstrate a 20-channel DWDM optical transmitter with a compact channel spacing of 100 GHz, being enabled by the Kerr microcomb source and micro-ring modulators (MRMs) array. By introducing channel de-interleaving architecture and the large-bandwidth MRM with high modulation efficiency, spectral aliasing and crosstalk are effectively mitigated, resulting in a single-channel data rate of 128 Gb/s and an ultra-high total capacity of 20×128 Gb/s, as well as a high spectral efficiency of 1.28 bps/Hz. Experimental results show open eye diagrams of high-speed four-level pulse amplitude signals and a low power consumption of 5.85 pJ/bit is achieved. This work underscores the potential of Kerr comb source and MRMs array for advanced optical transmitters, contributing to the development of high-capacity and low-power optical interconnects.