Etchless chalcogenide microresonators monolithically coupled to silicon photonic waveguides
Philippe Jean, Alexandre Douaud, Vincent Michaud-Belleau, Sandra Helena Messaddeq, Jérôme Genest, Sophie LaRochelle, Younès Messaddeq, Wei Shi
Abstract
Integration of chalcogenide waveguides in silicon photonics can mitigate the prohibitive nonlinear losses of silicon while leveraging the mature complementary metal–oxide–semiconductor (CMOS)-compatible nanophotonic fabrication process. In this work, we demonstrate, for the first time, to the best of our knowledge, a method of integrating high- <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>Q</mml:mi> </mml:math> chalcogenides microring resonators onto the silicon photonics platform without post-process etching. The method uses micro-trench filling and a novel thermal dewetting technique to form low-loss chalcogenide strip waveguides. The microrings are integrated directly inside silicon photonic circuits through evanescent coupling, providing an uncomplicated hybrid integration scheme without the need to modify the existing photonics foundry process. The microrings show a high quality factor exceeding <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mn>6</mml:mn> <mml:mo>×</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mn>10</mml:mn> <mml:mn>5</mml:mn> </mml:msup> </mml:mrow> </mml:math> near 1550 nm and propagation losses below 0.7 dB/cm, indicating a promising solution for low-cost, compact nonlinear photonic devices with applications in various fields such as telecommunications and spectroscopy.