A novel "Sawfish" photonic crystal cavity design is proposed for interfacing solid-state quantum emitters, specifically tin vacancy centers in diamond, with optical fibers for quantum network applications. The design was optimized to maximize the Purcell-enhanced emission coupling efficiency and adiabatic mode conversion from the nanocavity into a single-mode fiber. Full 3D finite element method (FEM) simulations and Bayesian optimization performed with JCMsuite were used to design and optimize the cavity, waveguide, and fiber coupling geometry, and to analyze its robustness to fabrication tolerances using surrogate modeling.
J. M. Bopp, et al. Sawfish Photonic Crystal Cavity for Near-Unity Emitter-to-Fiber Interfacing in Quantum Network Applications. Adv. Optical Mater. 12, 2301286 (2024).