AGF-based optimization for wideband flat directional coupling and microring resonating

In this work, we presented directional couplers with wideband flat coupling-ratio and a microring resonator with wideband uniform extinction-ratio (ER) based on artificial-gaugefield optimization. Proof-of-concept results are obtained on SOI and SiN platforms, with 0.9dB coupling-ratio variation and 1.6dB ER variation over 100nm bandwidth.