Periodic interactions between solitons and dispersive waves during the generation of non-coherent supercontinuum radiation

Manipulating Airy pulse in the regime of optical event horizon

A fiber analogue of the optical event horizon is proposed via an Airy-soliton collision. The characteristics of an Airy pulse are demonstrated in a photonic crystal fiber. The robust Airy wave packet is capable of being manipulated by a strong soliton in the frame of the Airy-soliton horizon, leading to various distinctive interaction scenarios. The Airy pulse realizes the temporal reversing and still maintains its features even after undergoing a complete wavelength conversion process. Different comb-like spectra are created in the presence of Raman effect by changing the duration of the Airy pulse. The rebounds of Airy pulse in a twin-soliton trapping process is investigated. Meanwhile, a "maximally compressed" Akhmediev Breather is employed to collide with a soliton to compare with the Airy-soliton horizon case. The result can be found in the potential applications of pulse reshaping and temporal-spectral imaging for optical communication and signal processing.

Trapping and controlling the dispersive wave within a solitonic well

We have numerically studied the effect of mutual interactions between soliton and dispersive waves and the possibility to create a solitonic well consisting of initial twin-solitons moving away from each other to trap the incident dispersive wave. Different from the case of the solitonic cage formed by the velocity-matched twin-solitons, the intense dispersive wave can break up into small pulses, which are almost completely trapped within the solitonic well. Moreover, the corresponding spectrum of the trapped dispersive wave can be narrowed firstly and then expanded, and a new dispersive wave can be generated as the twin-solitons collision occurred. By adjusting either the peak power or temporal width of incident dispersive wave, both the intensity of the collision-induced dispersive wave and the position where it is generated can be controlled.

Observation of the stepwise blue shift of a dispersive wave preceding its trapping by a soliton

The trapping of a weak dispersive wave by an intense soliton is a complex process occurring at the early stage of supercontinuum generation. It is theoretically predicted to arise from multiple soliton-dispersive wave interactions, producing a stepwise frequency blue shift of the dispersive wave. We report here the first experimental evidence of this frequency blue shift using a tapered fiber which acts as a prism, allowing to disperse the blue spectral components in order to identify unambiguously each soliton-dispersive wave collision.

Soliton trapping of dispersive waves in photonic crystal fiber with two zero dispersive wavelengths

Based on the generalized nonlinear Schrödinger equation, we present a numerical study of trapping of dispersive waves by solitons during supercontinuum generation in photonic crystal fibers pumped with femtosecond pulses in the anomalous dispersion region. Numerical simulation results show that the generated supercontinuum is bounded by two branches of dispersive waves, namely blue-shifted dispersive waves (B-DWs) and red-shifted dispersive waves (R-DWs). We find a novel phenomenon that not only B-DWs but also R-DWs can be trapped by solitons across the zero-dispersion wavelength when the group-velocity matching between the soliton and the dispersive wave is satisfied, which may led to the generation of new spectral components via mixing of solitons and dispersive waves. Mixing of solitons with dispersive waves has been shown to play an important role in shaping not only the edge of the supercontinuum, but also its central part around the higher zero-dispersion wavelength. Further, we show that the phenomenon of soliton trapping of dispersive waves in photonic crystal fibers with two zero-dispersion wavelengths has a very close relationship with pumping power and the interval between two zero-dispersion wavelengths. In order to clearly display the evolution of soliton trapping of dispersive waves, the spectrogram of output pulses is observed using cross-correlation frequency-resolved optical gating technique (XFROG).