Wang, FeifanZhao, LianfengXiao, YahuiLi, TiantianWang, YixiuSoman, AnishkumarLee, HwaseobKananen, ThomasHu, XiaoyongRand, Barry P.Gu, Tingyi2021-12-152021-12-152021-09-09Wang, Feifan, Lianfeng Zhao, Yahui Xiao, Tiantian Li, Yixiu Wang, Anishkumar Soman, Hwaseob Lee, et al. “Controlling Microring Resonator Extinction Ratio via Metal‐Halide Perovskite Nonlinearity.” Advanced Optical Materials 9, no. 22 (November 2021): 2100783. https://doi.org/10.1002/adom.202100783.2195-1071https://udspace.udel.edu/handle/19716/29540This article was originally published in Advanced Optical Materials. The version of record is available at: https://doi.org/10.1002/adom.202100783The exceptionally high optical nonlinearities, wide bandgap, and homogeneity in solution-processed metal-halide perovskite media are utilized as optical nonlinear elements on a silicon photonic platform for low-power-active components, such as all-optical switches, modulators, and lasers. With room temperature back-end-of-line compatible processing, a hybrid metal-halide perovskite (CH3NH3PbI3) microring resonator (MRR) structure is fabricated on a foundry-processed low-loss silicon photonic platform. With in-plane exci-tation near the light intensity of 110 W m−2, strong two-photon absorption and free-carrier absorption saturation are observed. With 103 field enhancements by MRRs, the photorefractive effect in the metal-halide perovskite reduces linear absorption, represented by 102 improvement of the MRR’s intrinsic quality factor and 20 dB enhancement of the extinction ratio.en-USabsorption saturationmicroring resonatorperovskitesphotorefractiontwo-photon absorptionArticle