High‐Capacity Data Transmission for Optical I/O Driven by Efficient Microcomb and Microring Modulator

The escalating demand for high‐speed, low‐power data transmission between processing units (XPUs) has underscored the limitations of traditional electrical input/output (I/O) technologies. Silicon photonics emerges as a promising solution for chip‐level optical I/O by integrating Kerr microcombs, microring‐based modulators, and photodetectors. In this study, a record‐breaking error‐free optical I/O transmission is demonstrated, achieving 2.3 Tbit s−1 per fiber port. This feat is enabled by dark soliton microcombs generated in a 400‐nm‐thick Si3N4 microring, exhibiting a high conversion efficiency (CE) of 49% and an on‐chip spectral bandwidth of 28 nm at −5 dBm, achieved through precise coupling and dispersion engineering. Utilizing a silicon microring modulator with an electro‐optic bandwidth of 61.7 GHz, 36 comb lines are encoded with PCIe6.0‐compatible 64 Gbit s−1 on‐off keying (OOK) signals. Additionally, these comb lines support 100 Gbit s−1 OOK per channel with a bit error rate (BER) of 10−10. The successful integration of these foundry‐compatible platforms confirms the viability of microcomb‐based optical I/O, paving the way for the next generation of high‐speed, energy‐efficient data communication systems.