Periodic evolution of the out-of-phase dipole and the single-charged vortex solitons in periodic photonic moiré lattice with saturable self-focusing nonlinearity media

Abstract

We survey the propagation properties of the out-of-phase (OOP) dipole solitons and the single-charged vortex (SCV) soliton in a periodic photonic moiré lattice with θ = arctan ⁡ ( 3 / 4 ) under self-focusing nonlinearity media. Since the rotation angle, periodic photonic moiré lattices have peculiar energy band structures, with highly flat bands and the bandgaps being much more extensive, which is very favorable for the realization and stability of the solitons. When exciting a single point on-site with the OOP dipole beam, its evolution shows a periodic rollover around the lattice axis. Whereas, when exciting a single point on-site with the SCV beam, it transmits counterclockwise rotating periodically. Both the OOP dipole solitons and the SVC soliton maintain the local state, but their phase exhibits different variations. The phase of the OOP dipole solitons is flipped, while that of the SCV is rotated counterclockwise. Our work further complements the exploration of solitons in photonic moiré lattice with nonlinearity.

The evolution of the out-of-phase dipole beams in the repulsive defect photonic moiré lattice with saturable self-focusing nonlinearity media

“…Under the nonlinear condition of V 0 = 30V, the transport properties of the OOP dipole beams in the repulsive defect photonic moiré lattice with θ= arctan (3/4) and ε = −0.5 are investigated comprehensively. The input beams could remain localized in the repulsive defect moiré lattice, as can be seen from the side-view of the beams in figure 4(a) (as previously reported in the paper [27]). Figures 4(b1)-(b4) shows the intensity distribution and phase structure at different distances, and the corresponding interferograms are shown in figures 4(c1)-(c4), which are obtained by interfering the OOP dipole beams with an inclined plane wave.…”

“…However, there are many open issues that remain to be explored. For example, the evolution of the SCV and doublecharged vortex (DCV) in square photonic lattices [37] and photonic moiré lattices [27] has been thoroughly studied. How do vortex beams (SCV and DCV) evolve in the repulsive defect moiré lattice?…”

“…By increasing the potential depth and decreasing the propagation constant, decay of unstable solitons can be arrested. In 2022, Zhang et al [26,27] thoroughly investigated the evolution of the Gaussian beam, out-of-phase (OOP) dipole beams, and single-charged vortex (SCV) in periodic photonic moiré lattices. In addition, moiré patterns composed of other sublattices, such as twisted honeycomb lattices [21,23] and Kagome lattices [28], have been investigated as well.…”

Light switching between localized and delocalized states in chiral moiré-like photonic lattice

“…By tuning the rotation angle, the conductive properties of graphene can be adjusted between superconductors and topological insulators, which opens up new fields for * Author to whom any correspondence should be addressed. condensed matter physics and photonics [6][7][8][9][10]. In photonics, moiré lattice pattern is reported by the incoherent superposition of two identical sublattice beams [11,12], e.g.…”

“…Besides, it is also demonstrated that the two-dimensional aperiodic moiré photonic lattice supports the localization of the probe beam due to the existence of a large number of flat bands, while the periodic lattice structure leads to the delocalized propagation of the beam due to the absence of flat bands [19]. Recently, researchers have found that the coherent superposition of two sets of relatively rotating light fields may lead to the moiré-like photonic lattice, which also follows the Pythagorean equation or the Diophantine equation, and the localization rules [8,10,19,20]. Related work in moirélike photonic lattice is arousing more interest due to its unique property.…”