Frequency Combs and Photonic Snakes

Optical frequency combs forming in microring cavities are revolutionising photonics' technologies, thanks to the temporal dissipative solitons [1], [2]. Important novel directions in this active research field are expected if dissipative solitons are formed in multi-dimensional geometries [3], as these support new types of solitons [4] and display special physical phenomena [5] with no direct one-dimensional counterparts. Here, we demonstrate an unexpected new type of stable two-dimensional nonlinear wave, namely the Photonic Snake [cf. Figs. 1(b)-(g)], which exists in cylindrical microcavities with normal dispersion and continuous diffraction along its axis. This system is well described by the hyperbolic two-dimensional damped-driven nonlinear Schrödinger equation, accounting for, dispersion, diffraction, loss, detuning, nonlinearity, and axially localised driving, respectively.