arXiv subjects

Xiankun Yao

Publications and source records attributed to Xiankun Yao.

5 recordsLinked to original sources

arXiv2025

Experimental observation of recurrence and spectral asymmetry of the two-component Akhmediev breathers in a single mode optical fibre

We report the results of experimental studies of recurrent spectral dynamics of the two component Akhmediev breathers (ABs) in a single mode optical fibre. We also provide the theoretical analysis and numerical simulations of the ABs based on the two component Manakov equations that confirm the experimental data. In particular, we observed spectral asymmetry of fundamental ABs and complex spectral evolution of second-order nondegenerate ABs.

physics.optics↗

arXiv2022

Heteroclinic-structure transition of the pure quartic modulation instability

We show that, in the pure-quartic systems, modulation instability (MI) undergoes heteroclinic-structure transitions (HSTs) at two critical frequencies of ω c1 and ω c2 ( ω c2 > ω c1 ), which indicates that there are significantchanges of the spatiotemporal behavior in the system. The complicated heteroclinic structure of instability obtained by the mode truncation method reveals all possible dynamic trajectories of nonlinear waves, which allows us to discover the various types of Fermi-Pasta-Ulam (FPU) recurrences and Akhmediev breathers (ABs). When the modulational frequency satisfies ω < ω c2 , the heteroclinic structure encompasses two separatrixes corresponding to the ABs and the nonlinear wave with a modulated final state, which individually separate FPU recurrences into three different regions. Remarkably, crossing critical frequency ω c1 , both the staggered FPU recurrences and ABs essentially switch their patterns. These HST behaviors will give vitality to the study of MI.

nlin.PS↗

arXiv2022

Non-degenerate multi-rogue waves and easy ways of their excitation

In multi-component systems, several rogue waves can be simultaneously excited using simple initial conditions in the form of a plane wave with a small amplitude single-peak perturbation. This is in drastic contrast with the case of multi-rogue waves of a single nonlinear Schrödinger equation (or other evolution equations) that require highly specific initial conditions to be used. This possibility arises due to the higher variety of rogue waves in multi-components systems each with individual eigenvalue of the inverse scattering technique. In theory, we expand the limited class of Peregrine-type solutions to a much larger family of non-degenerate rogue waves. The results of our work may explain the increased chances of appearance of rogue waves in crossing sea states (wind generated ocean gravity waves that form nonparallel wave systems along the water surface) as well as provide new possibilities of rogue wave observation in a wide range of multi-component physical systems such as multi-component Bose-Einstein condensates, multi-component plasmas and in birefringent optical fibres.

nlin.PS↗

arXiv2022

Modulation instability and non-degenerate Akhmediev breathers of Manakov equations

We reveal a new class of \textit{non-degenerate} Akhmediev breather (AB) solutions of Manakov equations that only exist in the focusing case. Based on exact solutions, we present the existence diagram of such excitations on the frequency-wavenumber plane. Conventional single-frequency modulation instability leads to simultaneous excitation of three ABs with two of them being non-degenerate.

nlin.PS↗

arXiv2018

Observation of the evolution dynamics from starting to shutting of SWNT-mode-locked fiber laser

Dispersive Fourier transform (TS-DFT) technique opens a fascinating pathway to explore the ultrafast non-repetitive even, which has been employed to study the build-up process of mode-locked lasers. Here the whole evolution dynamics (from starting up to shutting down) of conventional soliton (CS), stretched pulse (SP) and dissipative soliton (DS) are investigated by using TS-DFT technique. The relaxation oscillation can be always observed before the formation of stable pulse operation, which is stemmed from the inherent advantage of the single-walled carbon nanotube. However, owing to the different pulse features, they exhibit the distinct evolution dynamics in the starting and shutting processes. Some critical phenomena are observed, including transient complex spectrum broadening and frequency-shift interaction of SP and picosecond pulses. These results could further deepen the understanding of the mode-locked fiber laser from the real-time point of view and is helpful for the laser design and applications.

physics.optics↗