Initialization and Stabilization of Microring Resonators for Next-Generation Silicon Photonic Interconnects

The bandwidth bottleneck looming for traditional electronic interconnects necessitates the use of optical communications, as realized through the CMOS-compatible silicon nanophotonic platform. Within the silicon photonics platform, silicon microring resonators have received a great deal of attention for their ability to implement the critical functionalities of an on-chip optical network while offering superior energy-efficiency and low footprint characteristics. However, silicon microring-based structures have a large susceptibility to fabrication errors and changes in temperature. Integrated heaters that provide local heating of individual microrings offer a method to correct for these effects, but no large-scale solution has been achieved to automate their tuning process. In this context, we present the use of dithering signals as a method to automatically tune and stabilize microring resonators. We show that this technique can be manifested in low-speed analog & digital circuitry, lending credence to its ability to be scaled to a complete photonic interconnection network.