Presentation Information
[10p-A11-11]Investigation of Self-Injection Locking for Ultralow-Frequency-Noise Microcomb Sources Using MgF2 Microresonators
〇(D)Kai Yamaguchi1, Hiroki Moriguchi1, Zhiming Shi1,2, Hajime Kumazaki1,3, Hairun Guo2,4, Takasumi Tanabe1, Shun Fujii3 (1.Department of Electronics and Electrical Engineering, Faculty of Science and Technology, Keio University, 2.Laboratory of Specialty Fiber Optics and Optical Access Networks, Shanghai University, 3.Department of Physics, Faculty of Science and Technology, Keio UniversityKey, 4.Hefei National Laboratory, University of Science and Technology of China)
Keywords:
soliton,microcomb,self-injection lock
Recent advances in optical microcombs have enabled practical applications such as low-noise microwave generation and multi-wavelength light sources. In particular, self-injection locking (SIL) has attracted significant attention because it enables turnkey microcomb operation together with substantial frequency-noise reduction. Since the first demonstration of SIL-based microcomb generation, this technique has been investigated on various platforms. Among them, silicon nitride (SiN) microrings are widely used owing to their chip-scale integrability and high design flexibility, whereas crystalline MgF2 resonators are promising for ultralow-noise operation because of their exceptionally high Q factors and low thermo-optic coefficients. In this study, we demonstrate SIL-based microcomb generation using MgF2 resonators under both anomalous- and normal-dispersion regimes. We also compare the frequency-noise reduction effect between MgF2 and integrated 100-GHz-FSR SiN resonators using the same DFB laser. The MgF2 resonator exhibited a hertz-level intrinsic linewidth of 1.78 Hz, demonstrating strong potential as an ultralow-frequency-noise microcomb source.