About This Cover
20 October 2021, Volume 8, Issue 10, pp. 1243-1358
Ultrashort solitons interfere and create spectral fringes. Real-time spectroscopy resolves their rapid evolution and tracks the switching of soliton molecules inside a femtosecond fiber laser. See Nimmesgern et al., pp. 1334–1339. See print version of the cover.