Journal of Nonlinear Optical Physics & Materials

Zn:Yb:Tm:LiNbO₃ crystals with a range of [Li]/[Nb] ratios (0.94, 1.05, 1.20, and 1.38) were grown by Czochraski technique. The influence of [Li]/[Nb] ratio on the concentration of doped elements in grown crystal was investigated by inductively coupled plasma atomic emission spectrometry (ICP-AES). The defect structures formed at different [Li]/[Nb] ratios were studied by X-ray diffraction and INFRARED spectroscopy. The results show that, when the [Li]/[Nb] ratio increases, the segregation coefficients of ${\text{Yb}}^{3+}$ and ${\text{Tm}}^{3+}$ ions increase, while the segregation coefficient of ${\text{Zn}}^{2+}$ ions decreases. When the [Li]/[Nb] ratio in the melt increases to 1.20, the Zn:Yb:Tm:LiNbO₃ crystal approaches the stoichiometric ratio.

This paper deals with the investigation of the newly obtained solitary solutions of perturbed optical metamaterial with Kerr law nonlinearity. Two novel analytical techniques, namely, the extended Riccati equation rational expansion (ERERE) method and the extended rational $exp(-(\frac{{\phi }^{\prime }}{\phi })(\xi ))$-expansion (EREE) methods are applied to develop new solitary solutions. The resultant wave solutions are periodic wave solution, singular kink, anti-peakon, dark, singular anti-kink, anti-kink, gray and singular soliton solutions. The detailed dynamics of the retrieved solutions are the most potent influence of the proposed methods which shows the efficacy and fruitfulness of both the methods.

In this paper, the extended simplest equation method is utilized to construct the novel exact optical solitons solutions of the perturbed time fractional Chen–Lee–Liu equation with conformable fractional derivative. The acquired optical solitons and other solutions are expressed via the rational functions, the trigonometric functions, and the hyperbolic functions; in addition to guaranteeing the existence of the acquired results, the constrain conditions are provided. Furthermore, to elucidate the magnitude of the proposed equation, various obtained solutions are plotted via two-dimensional (2D) and three-dimensional (3D) graphs using appropriate values of parameters. It is observed that the present technique is a powerful tool and efficient for finding the analytical solution for nonlinear differential equations of integer and fractional orders.

Optics of negative index material is known for its unconventional results. In the perspective of nonlinear optics, it has a revolutionary impact. We, thus, investigate the effect of Kerr nonlinearity on the characteristics of a representative isotropic, frequency independent negative index material by defining an intensity-dependent effective permittivity and compare it to that in positive index material. Using the intensity-dependent permittivity, responses of essential characteristic features like phase and group velocities are studied and found to exhibit unconventional behavior with incident field intensity in the negative index material. At a threshold intensity, i.e., at an intensity at which effective permittivity vanishes, the material shows features of epsilon near zero and/or near zero index materials i.e., a diverging phase velocity with zero group velocity. The study shows the prospect of altering or tailoring characteristic features of a negative index material by tuning the field intensity of the propagating wave or pulse in the material.

The slow evaporation solution growth technique (SEST) was used to successfully grow inorganic single crystals of sodium sulphamate (NaS) in ambient conditions. The titled crystal’s structural and optical characteristics were evaluated using a variety of spectroscopic techniques. Powder X-ray diffraction (PXRD) analysis and Fourier transform infrared (FT-IR) spectroscopy were used to examine the crystal structure characteristics. Using UV-Vis spectroscopy, the optical properties of the NaS crystal were carefully examined, and the optical bandgap was determined using Tauc’s plot. The HR-XRD analysis examined crystalline perfection. Additionally, photoluminescence spectroscopy determined the emission spectra, and time-resolved photoluminescence measured the decay rate. The $Z$-scan technique was also used to examine the titled crystal’s nonlinear optical (NLO) performance.

This study reveals the dynamics of short optical pulses in nonlinear media. Then, for the survival of different types of solitary waves in the nonlinear medium, the constraint relations to the physical parameters and chirps associated with each of the solitary waves are explicitly shown. We authenticate numerically all those obtained from the analytical method and show the chirping effect is saturative in nature and can be managed by changing coefficients of inter-modal dispersion, stimulated Raman scattering (SRS), and self-steepening effect. We also verify the more operative condition of intermodal dispersion.

In this paper, we study the Radhakrishnan–Kundu–Lakshmanan equation (RKLE) that plays a key role in modeling the nonlinear propagation of the light pulses. Two novel methods namely Wang’s Bäcklund transformation-based method and Wang’s direct mapping method are employed to construct the diverse exact optical soliton solutions. Abundant exact solutions like the bright soliton solution, dark soliton solutions, singular soliton solutions, algebraic solitary wave solutions and the singular periodic wave solutions expressed in the form of the rational function type, double-exp function type, Sin-Cos function type, Tan function type, Cot function type, Sinh-Cosh function type, Tanh function type, Coth function type, Sech function type, Csch function type, Sec function type and Csc function type are obtained. The dynamics of the different exact solutions are presented through the 3D plot, contour and 2D curve, and the corresponding physical interpretations are elaborated in detail. It is confirmed that the proposed methods are effective and powerful, and can be adopted to construct the optical solitons of the other PDEs arising in the optical physics.

In this paper, the optical soliton and solitary wave solutions of the $(2+1)$-dimensional Mel’nikov equation are investigated using the Kudryashov $R$ function technique. The Kudryashov $R$ function approach has various features that significantly facilitate symbolic computing, particularly for highly dispersive nonlinear equations. In computations, this approach has the benefit of not requiring the use of a certain function form. This approach gives an algorithm that is straightforward, efficient, and simple for finding solitary wave solutions. In addition, this approach is very influential and reliable when it comes to discovering hyperbolic function solutions of nonlinear equations. Many new hyperbolic function solutions have been obtained from the governing equation by using this technique. In addition, numerous types of soliton solutions describing various structures of optical solitons are retrieved. Using this method, breather, W-shaped, bell shaped, and bright soliton solutions have been generated from the governing equation. From the obtained results, it can be asserted that the applied approach may be a useful tool for addressing more highly nonlinear problems in various fields. By choosing particular values for the relevant parameters, the dynamic features of some breather, W-shaped, bell shaped and bright soliton solutions to the $(2+1)$-dimensional Mel’nikov equation have been displayed in 3D, 2D and contour graphs.