Integrated Chalcogenide Photonics for Microresonator Soliton Combs

Abstract

AbstractIntegrated nonlinear photonics, combined nonlinear optics with state‐of‐the‐art photonic integration, play a crucial role in chip‐integrated technologies including optical frequency combs, molecular spectroscopy, and quantum optics. Optical materials with favorable properties are the foundation to promote integrated photonic devices with bandwidth, efficiency, and flexibility in high‐volume chip‐scale fabrication. In this work, a newly developed chalcogenide glass‐Ge25Sb10S65 (GeSbS) is presented for nonlinear photonic integration and for dissipative soliton microcomb generation. The GeSbS features wide transparency (0.5–10 µm), strong nonlinearity (1.3 × 10−18 m2 W−1), and low thermo‐refractive coefficient (3.1 × 10−5 K−1), and is complementary metal oxide semiconductor (CMOS)‐compatible in fabrication. In this platform, chip‐integrated optical microresonators with an average intrinsic quality (Q) factor of ≈1.97 × 106 are implemented, and lithographically controlled dispersion engineering is carried out. In particular, both a bright soliton‐based microcomb with bandwidth of 240 nm (≈1440–1680 nm) and a dark‐pulse comb with bandwidth of 80 nm (≈1510–1590 nm) are generated in a single microresonator in its separated fundamental polarized mode families.The ten‐milliwatt level of soliton microcomb operation power facilitates the monolithically integrated photonic circuits. The results provide a potential material platform for integrated nonlinear photonics for highly compact and high‐intensity nonlinear interactions in visible and infrared regions.