This study quantitatively identifies contaminant loss as the dominant limitation for silica microcavity Q factors. Through laser polishing and thermal annealing, a record-high Q of 8.28 × 10⁹ is achieved, enabling fully stabilized soliton microcombs with >60.6 dB repetition-rate phase-noise suppression.
- Ting-Yang Pan
- Teng Tan
- Bai-Cheng Yao
