Angled 3D Glass-to-Silicon Photonics Coupling Interface

A numerical study on the design of a novel low-loss, low-cost, and low fabrication complexity, angled 3D Glass-to-SiPh coupling interface is demonstrated. The interface is composed of a 2° angled 3D glass waveguide and a thin-silicon-on-insulator platform flip-chip assembled in close proximity. The overall structure is designed and optimized based on the maximization of the coupling strength ( $\kappa )$ as well as the calculation of a constant loss taper (CLT) silicon taper. The reported maximum conversion efficiency is 85.7% for 1.55- $\mu \text{m}$ central wavelength and is almost flat across the entire $C$ -band. The results were obtained using a 3D eigenmode expansion (3D-EME) propagation solver and were verified through the 3D finite-difference time-domain (3D-FDTD) simulation method.