Silicon Photonic Microdisk Modulator With Sub fJ/Bit Energy Consumption

The advances of silicon photonics modulators in recent years have paved the road to establish high-speed and low-power optical links in data center. Inter-chip optical interconnects within the rack have rigorous requirements on bandwidth density and energy consumption. Silicon microdisk modulators have become increasingly attractive due to the advantages of small footprint, low energy consumption, as well as lower sidewall roughness scattering than microring structures. In this work, we experimentally demonstrate a high-speed silicon microdisk modulator with lateral junction and fabricated by standard foundry process. A free spectral range of 2.5 THz and a 3-dB bandwidth of 45 GHz are measured. Clear and open eye diagram up to 168 Gb/s four-level pulse amplitude modulation is obtained with 1.8 Vppdriving voltage, corresponding to an ultra-low energy consumption of 0.99 fJ/bit.