Soliton microcomb generation in packaged high-Q silica microrod cavities for long-term and reproducible operations

High-Q whispering-gallery mode resonators are key building blocks for nonlinear photonics, yet their practical applications are limited by the delicate coupling conditions, and hence remain challenging due to the need for stable but flexible coupling. Here, we demonstrate a restorable coupling strategy for silica microrod resonators, in which the spacing between the coupling fiber and microresonator can be precisely managed so as to mitigate the residual mechanical stress and preserve device integrity. To ensure reproducible operation, we implement a ringdown referencing mechanism that serves as a quantitative anchor for re-accessing target resonant states. Our packaged microresonators are able to maintain intrinsic quality factors exceeding 10⁹ for over six months, and the modules remain capable of regenerating soliton frequency combs after long-term storage. Our approach enables environmentally stable resonators with ultralow optical loss and nonlinear functionality that are durable and reproducible, supporting robust deployment of high-Q microresonators.