Nonlocal gap solitons inPT-symmetric periodic potentials with defocusing nonlinearity

Abstract

Existence and stability of PT -symmetric gap solitons in a periodic structure with defocussing nonlocal nonlinearity are studied both theoretically and numerically. We find that, for any degree of nonlocality, gap solitons are always unstable in the presence of an imaginary potential. The instability manifests itself as a lateral drift of solitons due to an unbalanced particle flux. We also demonstrate that the perturbation growth rate is proportional to the amount of gain (loss), thus predicting the observability of stable gap solitons for small imaginary potentials.

Nonlinear switching and solitons in PT‐symmetric photonic systems

“…Defocusing type of nonlinearity has been considered in [120]. The existence and stability of gap solitons in media with diffusive-like nonlinear response were determined.…”

Propagation of anomalous vortex beams in strongly nonlocal nonlinear media

“…Based on Eqs. (11) and (12), we obtain the critical input powers of AVBs in SNNM numerically (see Fig. 1).…”

“…Until 1993, the (2 þ1)-dimensional spatial optical solitons were observed in photorefractive media, which is an epochmaking event [3] because it is found that the saturation nonlinearity can suppress the catastrophic collapse. Nowadays, various solitons have been found in different media, such as surface solitons [4][5][6][7][8][9], PT-symmetric potential solitons [10][11][12][13][14], optical lattice solitons [15][16][17][18][19][20], and even spatiotemporal optical solitons (namely the light bullets) [21][22][23][24][25][26][27], and so on. Recently, it is found that except the saturation nonlinearity, the nonlocal nonlinearity can also suppress the catastrophic collapse in bulk media.…”

Nonlocal gray solitons in parity-time-symmetric potentials with spatially modulated nonlinearity

“…Bright solitons can also exist in PT-symmetric potentials with nonlocal nonlinearity [27][28][29][30][31][32]. Nonlocal fundamental and dipole defect solitons can exist in different gaps in PT-symmetric optical lattices with focusing nonlinearity [27].…”