We analyze the transverse instabilities of spatial bright solitons in nonlocal nonlinear media, both analytically and numerically. We demonstrate that the nonlocal nonlinear response leads to a dramatic suppression of the transverse instability of the soliton stripes, and we derive the asymptotic expressions for the instability growth rate in both short-and long-wave approximations. c 2017 Optical Society of America OCIS codes: 190.3270 190.4420 190.6135 Symmetry-breaking instabilities have been studied in different areas of physics, since they provide a simple means to observe the manifestation of strongly nonlinear effects in nature. One example is the transverse instabilities of spatial optical solitons [1] associated with the growth of transverse modulations of quasi-onedimensional bright and dark soliton stripes in both focusing [2-4] and defocusing [5] nonlinear media. In particular, this kind of symmetry-breaking instability turns a bright-soliton stripe into a array of two-dimensional filaments [6] and bends a dark-soliton stripe creating pairs of optical vortices of opposite polarities [7]. Consequently, the transverse instabilities set severe limits on the observation of one-dimensional spatial solitons in bulk media [8].Several different physical mechanisms for suppressing the soliton transverse instabilities have been proposed and studied, including the effect of partial incoherence of light [9,10] and anisotropic nonlinear response [10] in photorefractive crystals, and the stabilizing action of the nonlinear coupling between the different modes or polarizations [11]. Recently initiated theoretical and experimental studies of nonlocal nonlinearities revealed many novel features in the propagation of spatial solitons including the suppression of their modulational [12] and azimuthal [13] instabilities. In this Letter we demonstrate that significant suppression of the soliton transverse instabilities can be achieved in nonlocal nonlinear media, and we derive analytical results for the instability growth rate in both long-and short-scale asymptotic limits.We consider the propagation of an optical beam in a nonlocal nonlinear medium described by the normalized two-dimensional nonlinear Schödinger (NLS) equation,where ∆ ⊥ = ∂ 2 /∂x 2 + ∂ 2 /∂y 2 , E = E(x, y; z) is the slowly varying electric field envelope, n = n(x, y; z) is the optical refractive index, and the parameter d stands for the strength of nonlocality. The model (1) describes the light propagation in different types of nonlocal nonlinear media including nematic liquid crystals [14].We look for stationary solutions of Eq. (1) in the form of the bright soliton stripes, E(x, y; z) = u(x) exp(iβz), where u(x) is a (numerically found) localized function, u(±∞) = 0, and β is the (real) propagation constant.The transverse instability of quasi-one-dimensional solitons in nonlocal nonlinear media is investigated by a standard linear stability analysis [1], by introducing the perturbed solution in the form: n = n 0 (x) + ǫδn, andwhere (u 0 , n 0 ) i...
We theoretically and experimentally generate stationary crescent surface solitons pinged to the boundary of a microstructured vertical cavity surface emission laser by triggering the intrinsic cavity mode as a background potential. Instead of a direct transition from linear to nonlinear cavity modes, we demonstrate the existence of symmetry-breaking crescent waves without any analogs in the linear limit. Our results provide an alternative and general method to control lasing characteristics as well as to study optical surface waves.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.