Dispersion Engineered High-Quality Ge–Sb–S Reflowed Wedge Resonator

Dispersion engineering in chalcogenide integrated photonics is crucial for nonlinear optical applications. We have developed a thermal-reflow-assisted fabrication method that creates Ge₂₃Sb₇S₇₀ reflowed wedge resonators with supreme surface roughness and quality factors exceeding ${{10}^6}$. Our simulations show the ability to engineer the dispersion of their whispering-gallery modes to overcome large material dispersion in near-infrared wavelength and achieve anomalous dispersion. We have successfully fabricated the designed tightly confined reflow bump geometry and experimentally demonstrate an engineered flat anomalous dispersion of the supported TM₀₀ optical mode.