Stability of multipole-mode solitons in thermal nonlinear media

Abstract

We study the stability of multipole-mode solitons in one-dimensional thermal nonlinear media. We show how the sample geometry impacts the stability of multipole-mode solitons and reveals that the tripole and quadrupole can be made stable in their whole domain of existence, provided that the sample width exceeds a critical value. In spite of such geometry-dependent soliton stability, we find that the maximal number of peaks in stable multipole-mode solitons in thermal media is the same as that in nonlinear materials with finite-range nonlocality.

Solution for (1+1)-dimensional surface solitons in thermal nonlinear media

“…When the sample width is smaller than three times the beam width, I | x=0 is not negligible, e.g., I | x=0 /I max ≈ 0.1 for d/w 0 = 2, and the surface soliton can not exist due to the influence of the left boundary. This property is identical with that of solitons in bulk media [26].…”

“…It can be seen that there exists little difference between the numerical solution and the analytical solution. It is known that surface dipole solitons are stable [23] and, analogously, quadropole solitons in bulk media are stable too [26]. The difference between the numerical solution and the approximate analytical solution can be considered as a perturbation, which leads to some spatial oscillations in propagation when the analytical solution is used as the initial profile, as shown in Fig.…”

Solitons supported by complexPT-symmetric Gaussian potentials

“…In local Kerr-type media, fundamental solitons are stable, whereas multimode solitons are unstable. Otherwise, multimode solitons have been studied in nonlocal nonlinear media theoretically and experimentally [18][19][20]. Many authors have paid much attention to multimode solitons in optical lattices too [21][22][23].…”

Multiple-type solutions for multipole interface solitons in thermal nonlinear media

“…It is known that the solitons in bulk thermal media are unstable when the number of peaks is more than 4 [20,21]. However, for the fifth-order interface solitons, there exists a stability region, although this region (not given here) is very small.…”

“…Nonlocal multipole solitons are studied in nematic liquid crystals [20] and lead glass [15,21] for both bulk solitons and surface solitons. In nonlocal bulk media, multipole solitons are symmetric, and they are stable if they contain fewer than five peaks [20,21].…”