Gap solitons supported by two-dimensional parity-time-symmetric optical lattices in saturable media with fourth-order diffraction

Abstract

The existence and the stability of in-phase dipole gap solitons in two-dimensional (2D) paritytime (PT)-symmetric optical lattices with defocusing saturable nonlinearity and a fourth-order diffraction property are investigated. When different values are used for the coupling constant of the fourth-order diffraction, the critical threshold of the 2D PT-symmetric optical lattices remains unchanged. The in-phase dipole solitons exist in the first finite gap and are shown to be stable in the moderate power region. The existence and stability of dipole solitons with different fourthorder diffraction coupling constants and different saturation parameters are therefore studied. We also investigate the transverse power-flow vector of these gap solitons.

One-dimensional PT -symmetric eigenmodes in k-wave number Scarf II potential with defocusing nonlinearity

“…Gross-Pitaevskii equations with Wadati class of potentials have a special interest while studying the  -symmetric systems [16][17][18].  -symmetric soliton models with Kerr nonlinearity in single [19][20][21][22][23][24][25][26][27] and coupled systems [28][29][30][31][32] have been studied extensively. Apart from Kerr nonlinear system, different kinds of nonlinear models such as nonlocal [33,34], variable coefficient [35], parabolic law [36], cubic-quintic [37,38], cubic-quartic [39], quintic-septimal [40,41] and cubic-quintic-septimal [42] nonlinear Schrodinger equations leading to different types of soliton solutions have been studied.…”

“…Dark soliton dynamics, stability, interactions, phase dynamics, ultra-short dark soliton, vector dark solitons, their tunnelling effects etc in nonlinear lossless and lossy mediums are theoretically explored. [58][59][60][61][62][63][64][65] Relevant studies on the dark-bright vector soliton in fibre ring lasers [66], robust dark topological valley Hall edge soliton [67], dark soliton families in quintic nonlinear lattices [68], and dark gap solitons in nonlinear media with fourth-order dispersion [25,69] are reported recently. The dark gap soliton in Bose-Einstein codensates trapped by optical lattices is predicted both in defocusing cubic [70] and quintic [71] nonlinearity.…”