Multi-frequency radiation of dissipative solitons in optical fiber cavities

Abstract

New resonant emission of dispersive waves by oscillating solitary structures in optical fiber cavities is considered analytically and numerically. The pulse propagation is described in the framework of the Lugiato-Lefever equation when a Hopf-bifurcation can result in the formation of oscillating dissipative solitons. The resonance condition for the radiation of the dissipative oscillating solitons is derived and it is demonstrated that the predicted resonances match the spectral lines observed in numerical simulations perfectly. The complex recoil of the radiation on the soliton dynamics is discussed. The reported effect can have importance for the generation of frequency combs in nonlinear microring resonators.

Observations of Existence and Instability Dynamics of Near-Zero-Dispersion Temporal Kerr Cavity Solitons

“…This has been achieved by using an experimental configuration that allows operation (arbitrarily) close to the ZDW of the resonator, thus enabling systematic control over the relative impact of third-order dispersion. Our results include the first observations of polychromatic dispersive waves emitted by breathing near-zero-dispersion CSs, as predicted by earlier theories [36]. Moreover, we have shown that, for low driving powers, third-order dispersion can stabilize CSs (as predicted by earlier theories [37]), but that for high-power levels, the effect of third-order dispersion switches from stabilizing to destablizing, expanding the range of parameters over which solitons are unstable.…”

“…Our experiments are performed in a coherently driven fibre ring resonator, where the dispersion conditions are systematically controlled by tuning the driving wavelength [34]. Our results provide experimental confirmation of the theoretical predictions mentioned above [36,37]. First, we observe the emission of polychromatic dispersive radiation emitted by breathing solitons.…”

“…In stark contrast, at ∆ = 18, the solitons exhibit regular oscillations with a period of about T osc = 1.59 µs (or equivalently 70 roundtrips), with the dispersive wave peak exhibiting a manifestly polychromatic character. The latter feature was recently predicted by Melchert et al [36] and can be explained as follows. Efficient dispersive wave emis-sion requires that the CS spectrally overlaps with the phase-matched dispersive wave wavelength [42]; when the (spectral width of the) CS oscillates, the efficiency of dispersive wave emission is accordingly modulated.…”

“…In this regime, higher-order dispersion dominates the dynamics, giving rise to novel bright localized structures both in the normal and anomalous dispersion regimes [33][34][35]. Theoretical studies have also suggested that near-zero-dispersion conditions can significantly affect the solitons' instability dynamics and range of existence [36,37]. In particular, it has been theoretically predicted that (i) strong third-order dispersion combined with soliton breathing can lead to the emission of comblike, polychromatic dispersive radiation [36] -in stark contrast to the sharp, monochromatic dispersive radiation that is commonly observed with stable (i.e.…”

“…Theoretical studies have also suggested that near-zero-dispersion conditions can significantly affect the solitons' instability dynamics and range of existence [36,37]. In particular, it has been theoretically predicted that (i) strong third-order dispersion combined with soliton breathing can lead to the emission of comblike, polychromatic dispersive radiation [36] -in stark contrast to the sharp, monochromatic dispersive radiation that is commonly observed with stable (i.e. nonoscillatory) solitons [29,34] -and that (ii) third-order dispersion can stabilize CSs, i.e., restrict the range of parameters over which the solitons are oscillatorily unstable [37].…”