Extended Data Fig. 1: Durability tests of optical references.
From: Microresonator-referenced soliton microcombs with zeptosecond-level timing noise
(a), Transmission spectra of a mode recorded from a packaged MgF2 microresonator before (upper panel) and after 4 months of operation (lower panel). Intrinsic Q factors are extracted from Lorentzian fits. (b), Transmission spectra of a packaged MgF2 microresonator before and after vibration test (see Supplementary Movie). (c), Transmission spectra of two modes before and after the vibration test. Intrinsic and external Q factors are extracted from Lorentzian fits.
