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 Ge<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">23</sub>Sb<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7</sub>S<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">70</sub> reflowed wedge resonators with supreme surface roughness and quality factors exceeding 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup>. 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 TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">00</sub> optical mode.