On-Chip 3.2 Tb/s Wireless Optical Interconnects Using Diffraction-Free Beam and Microcomb

On-chip optical interconnection is a promising technology to alleviate the bandwidth bottleneck in high-performance computing. Compared with wired optical interconnection, wireless manner can significantly lower the complexity, benefitting from weak optical confinement in both vertical and transverse directions. However, the diffraction nature of Gaussian beam makes the state-of-art wireless schemes difficult to fulfill high-data-rate transmission due to tens of decibels of loss. Meanwhile, diffraction-free beam with power-concentrated, self-bending and self-healing properties shows great potential in low-loss, long-distance, reconfigurable and robust propagation. Here, we propose an on-chip wireless interconnection scheme based on diffraction-free beam by using tunable phase mask to generate, repeat and switch beams. Loss is effectually reduced via the retained vertical confinement combined with the transverse diffraction-free beam construction. Millimeter-scale transmission, which is one order of magnitude higher than the state-of-art wireless scheme with the same loss, is enabled. Reconfigurable switch is presented with > 20 dB extinction ratio and high scalability, while the high robustness and healing in scattering environments are also confirmed. As a proof-of-concept demonstration, a wireless network containing four intersected beams is verified to transmit signal at 3.2 Tb/s aggregated data rate per beam, driven by optical soliton microcomb.