Enhanced nonreciprocal transmission through a saturable cubic-quintic nonlinear dimer defect

Abstract

The transmission properties through a saturable cubic-quintic nonlinear defect attached to lateral linear chains is investigated. Particular attention is directed to the possible non-reciprocal diode-like transmission when the parity-symmetry of the defect is broken. Distinct cases of parity breaking are considered including asymmetric linear and nonlinear responses. The spectrum of the transmission coefficient is analytically computed and the influence of the degree of saturation analyzed in detail. The transmission of Gaussian wave-packets is also numerically investigated. Our results unveil that spectral regions with high transmission and enhanced diode-like operation can be achieved.

Multichannel asymmetric transmission through a dimer defect with saturable inter-site nonlinearity

“…Equation (29) can be understood by a direct are found to be τ + = 0.797 and τ − = 0.819, and the corresponding rectifying factor is found to be f = −0.013. Thus, increasing saturation implies that the transmission increases but the asymmetry decreases significantly, as was also found in previous works for on-site saturability [8,11]. This is also consistent with results for the stationary transmission, e.g., by comparing middle left plot in Fig.…”

“…Note that, in contrast to previously studied DNLS-type transmission problems (e.g., [2][3][4][5][6][7][8][9][10][11]), Eq. ( 17) does not necessarily determine the transmission coefficient for a plane wave of wave vector k as a unique function of the transmitted intensity |T | 2 , since in presence of intersite nonlinearities, there may be multiple solution branches i corresponding to the same |T | 2 but with different phases ϕ i ≡ arg(T ).…”

“…A similar study was carried out for saturable nonlinear oligomer DNLS segments (N = 1, 2, 3) embedded in a linear Schrödinger chain [9]. Other relevant works concern the asymmetric wave transmission through oligomers with cubic-quintic on-site nonlinearity [10], and the enhancement of the non-reciprocal transmission under saturable cubic-quintic nonlinear responses for dimers [11].…”

“…The parameter γ n determines the strength of the local nonlinearity, which we take to have a standard cubic (Kerr) form, while n represents the nonlocal (inter-site) saturable nonlinearity. We saturate only the inter-site nonlinearity as the effect of saturating the on-site cubic nonlinearity has been addressed in earlier work [7][8][9]11]. β is the saturation parameter; in the unsaturated limit β = 0 we recover the DNLS model with cubic inter-site nonlinearity studied in [18] (relevant e.g.…”

Effects of dispersion and saturable nonlinearity on dissipative solitons

“…16,17) The existence of nonlinearity saturation has motivated several interesting works in the framework of both generalized and fractional NLS models. [18][19][20][21] The objective of the present paper is to investigate the effects of perturbations, namely, dissipative loss, IPRS and TPA on a fundamental soliton propagating in saturable cubicquintic nonlinear media in presence of nonlinear dispersion. In the absence of saturable nonlinearity, a number of studies based on variational techniques, soliton perturbation theory, the inverse scattering method, Lie symmetry analysis, and Laplace-Adomian decomposition method have been carried out to understand the effects of different types of perturbations.…”