Design and fabrication of high-Q and low-loss ZnMgO optical microring resonators

This study presents the design and fabrication of high-quality factor (Q) and low-loss zinc magnesium oxide (ZnMgO) optical microring resonators (MRRs) using the photonic damascene process. ZnMgO, known for its excellent linear and nonlinear optical properties, was employed to achieve effective refractive index matching and low propagation losses. The fabricated MRRs demonstrated a maximum intrinsic quality factor (Qint) of 1.18 × 10⁵ in the TE₀₀ mode, with a corresponding propagation loss of 2.52 dB/cm, and 9.0×10⁴ in the TM₀₀ mode, with a propagation loss of 3.27 dB/cm. The coupling coefficient (κ) was found to decrease with increasing coupling gap, consistent with theoretical models. These results highlight ZnMgO as a promising material for integrated nonlinear optical platforms, offering potential applications in optical communication, sensing, and other fields. Future research aims to further explore novel MRR structures and enhance their stability and reliability for advanced photonic devices.