Silicon Photonic DWDM Micro-Resonator Link Initialization Under Fabrication Variation

Silicon photonic dense wavelength-division multiplexing (DWDM) links based on microresonators are a leading candidate for scaling optical interconnects in high-performance computing. However, fabrication-induced variations in resonant frequencies, free spectral ranges (FSRs), and thermal tuning efficiencies necessitate robust initialization strategies to align resonators with multi-wavelength laser sources. While many prior studies examine individual devices, comprehensive wafer-scale statistical analyses—and their implications for initialization algorithms remain scarce. Here, we report measurements from more than 4,600 fabricated resonators, including microdisks, tapered hybrid-bend (THB) racetracks, and microrings, fabricated on 300-mm wafers. We show that microrings exhibit the largest variation, while microdisks are significantly more uniform. Using these distributions, we evaluate initialization performance through Monte Carlo simulations of two widely used algorithms: barrel-shifting and global-search. Our results establish a clear tradeoff: barrel-shifting offers sub-millisecond initialization with modest power budgets for low-variation devices (e.g. microdisks), whereas global search, though approximately 300 times slower, achieves substantially lower power consumption for high-variation devices (e.g. microrings). This work provides the first wafer-scale statistical framework linking resonator variability to initialization outcomes, and offers practical design guidance for selecting initialization strategies that balance speed, power, and robustness.