Integrated multi-port multi-wavelength coherent optical source for beyond Tb/s optical links

Microcomb-based sources formed by placing an integrated demultiplexer with an ultra-low power consumption after an efficient optical frequency comb play a key role in many large-scale optical links for data centers and AI systems. Here, we demonstrate a multi-wavelength multi-port source based on a Kerr microcomb followed by a monolithically-integrated demultiplexer, which autonomously locks to and tracks the comb lines. Mach-Zehnder interferometer- and ring resonator-based wavelength demultiplexers, implemented using capacitive optical phase shifters with a zero static power consumption, and a soliton microcomb, with a 200 GHz mode-spacing and 53% efficiency, are implemented. Using a single control unit for the sequential control of all phase shifters, a total demultiplexer power consumption of 2.4 mW is achieved, which corresponds to a record demultiplexer energy consumption of 10fJ/b and 2.5fJ/b for an 8-channel and 32-channel systems at a data-rate of 32 Gb/s/channel, respectively, significantly improving the demultiplexer energy efficiency compared to the thermally-tuned state-of-the-art systems.