Silicon photonics holds significant promise in revolutionizing optical interconnects in data centers and high performance computers to enable scaling into the Pb/s package escape bandwidth regime while consuming orders of magnitude less energy per bit than current solutions. In this work, we review recent progress in silicon photonic interconnects leveraging chipscale Kerr frequency comb sources and provide a comprehensive overview of massively scalable silicon photonic systems capable of capitalizing on the large number of wavelengths provided by such combs. We first consider the high-level architectural constraints and then proceed to detail the corresponding fundamental device designs supported by both simulated and experimental results. Furthermore, the majority of experimentally measured devices were fabricated in a commercial 300 mm foundry, showing a clear path to volume manufacturing. Finally, we present various system-level experiments which illustrate successful proof-ofprinciple operation, including flip-chip integration with a codesigned CMOS application-specific integrated circuit (ASIC) to realize a complete Kerr comb-driven electronic-photonic engine. These results provide a viable and appealing path towards future co-packaged silicon photonic interconnects with aggregate perfiber bandwidth above 1 Tb/s, energy consumption below 1 pJ/bit, and areal bandwidth density greater than 5 Tb/s/mm 2 .

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We demonstrate an ultra-broadband silicon photonic interleaver capable of interleaving and de-interleaving frequency comb lines over a 125 nm bandwidth in the extended Cand L-bands. We use a ring-assisted asymmetric Mach Zehnder interferometer to achieve a flat-top passband response while maintaining a compact device footprint. The device has a 400 GHz free spectral range to divide an optical frequency comb with 200 GHz channel spacing into two output groups, each with a channel spacing of 400 GHz, yielding a potential capacity of 78 total wavelength-division multiplexed channels between 1525 nm and 1650 nm. This device represents an important step towards realizing highly parallel integrated optical links with broadband frequency comb sources within the silicon photonics platform.Index Terms-Silicon photonics, optical frequency combs, wavelength division multiplexing.

We demonstrate the first o n-chip silicon photonic transmitter u sing a Kerr frequency comb source for massive wavelength parallelism. The architecture is scalable to hundreds of wavelength channels, paving the way for multi-Tb/s photonic interconnects.