PICO: Mitigating heterodyne crosstalk due to process variations and intermodulation effects in photonic NoCs

Photonic networks-on-chip (PNoCs) employ photonic waveguides with dense-wavelength-division-multiplexing (DWDM) for signal traversal and microring resonators (MRs) for signal modulation, to enable high bandwidth on-chip transfers. Unfortunately, DWDM increases susceptibility to intermodulation effects, which reduces signal-to-noise ratio (SNR) for photonic data transfers. Additionally, process variations induce variations in the width and thickness of MRs causing resonance wavelength shifts, which further reduces SNR, and creates communication errors. This paper proposes a novel framework (called PICO) for mitigating heterodyne crosstalk due to process variations and intermodulation effects in PNoC architectures. Experimental results indicate that our approach can improve the worst-case SNR by up to 4.4× and significantly enhance the reliability of DWDM-based PNoC architectures.