Collision between a dark soliton and a linear wave in an optical fiber.

We report an experimental observation of the collision between a linear wave propagating in the anomalous dispersion region of an optical fiber and a dark soliton located in the normal dispersion region. This interaction results in the emission of a new frequency component whose wavelength can be predicted using phase-matching arguments. The measured efficiency of this process shows a strong dependency with the soliton grayness and the linear wave wavelength, and is in a good agreement with theory and numerical simulations.

Grayness-dependent emission of dispersive waves from dark solitons in optical fibers.

We report the experimental observation of dispersive wave emission from gray solitons propagating in the normal dispersion region of an optical fiber. Besides observing for the first time, to the best of our knowledge, the emission of a dispersive wave from an isolated dark soliton, we show that the dispersive wave frequency and amplitude strongly depend on soliton grayness. This process can be explained by the higher-order dispersion contribution into the phase-matching condition and the grayness of the soliton. Numerical simulations and theoretical predictions are in good agreement with the experiments.

Longitudinal soliton tunneling in optical fiber.

We report the observation of the longitudinal soliton tunneling effect in axially varying optical fibers. A fundamental soliton, initially propagating in the anomalous dispersion region of a fiber, can pass through a normal dispersion barrier without being substantially affected. We perform experimental studies by means of spectral and temporal characterizations that show the evidence of the longitudinal soliton tunneling process. Our results are well supported by numerical simulations using the generalized nonlinear Schrödinger equation.

Spectral wings of the fiber supercontinuum and the dark-bright soliton interaction.

We present experimental and numerical data on the supercontinuum generation in an optical fiber pumped in the normal dispersion range where the seeded dark and the spontaneously generated bright solitons contribute to the spectral broadening. We report the dispersive radiation arising from the interaction of the bright and dark solitons. This radiation consists of the two weak dispersing pulses that continuously shift their frequencies and shape the short and long wavelength wings of the supercontinuum spectrum.

Emission of dispersive waves from a train of dark solitons in optical fibers.

We report the experimental observation of multiple dispersive waves (DWs) emitted in the anomalous dispersion region of an optical fiber from a train of dark solitons. Each DW can be associated to one dark soliton of the train, using phase-matching arguments involving higher-order dispersion and soliton velocity. For a large number of dark solitons (>10), we observe the formation of a continuum associated with the efficient emission of DWs.