Ultrathin BP QDs with a uniform size of ∼3.4 nm were prepared via small molecule-assisted liquid phase exfoliation and they exhibited superior broadband nonlinear saturable absorption promising for nonlinear optical applications. Laser photolysis measurement implied that the nonlinear response origin was related to the long-lived electron-hole pairs delocalized within the BP QDs.

We directly measure the nonlinear optical response in argon and nitrogen in a thin gas target to laser intensities near the ionization threshold. No instantaneous negative nonlinear refractive index is observed, nor is saturation, in contrast with a previous measurement [Opt. Express 17, 13429 (2009)] and calculations [Phys. Rev. Lett. 106, 183902 (2011)]. In addition, we are able to cleanly se...

We present an overview of the properties of nonlinear guided waves and (bright and dark) spatial optical solitons in a periodic medium created by linear and nonlinear waveguides. First we consider a single layer with a cubic nonlinear response (a nonlinear slab waveguide) embedded in a periodic layered linear medium and describe nonlinear localized modes (guided waves and Bragg-like localized g...

We present the spectral and nonlinear optical properties of ZnO-SiO2 nanocomposites prepared by colloidal chemical synthesis. Obvious enhancement of ultraviolet (UV) emission of the samples is observed, and the strongest UV emission of a typical ZnO-SiO2 nanocomposite is over three times stronger than that of pure ZnO. The nonlinearity of the silica colloid is low, and its nonlinear response ca...

introduction the purpose of the current study was to determine optical sensitivity of n-isopropyl acrylamide nipam and polyacrylamide gelatin and tetrakis hydroxymethyl phosphoniun chloride (pagat) polymer gels for different wavelength of visible light spectrum applied in optical computed tomography method. materials and methods nipam and pagat polymer gels with conventional formulations used f...

Linear as well as nonlinear optical responses of slab waveguides with one-dimensional periodic structures at the scale of optical wavelengths are reviewed. By inserting an inorganic-organic hybrid semiconductor into the periodic structure, we demonstrated strong modification of optical response. The strong coupling (polariton) effect, directional photoluminescence, exciton super-radiance and tr...

Nonlinear-optical response of photorefractive hybrid liquid crystal (LC) cells has been studied by means of dynamic holographic technique in two-wave mixing arrangement. The LC cells include nonuniform silicon substrates comprising a micrometer-range photonic crystal. A thin LC layer is set between silicon substrate and a flat glass substrate covered by a transparent (ITO) electrode. A dynamic ...

Among other significant obstacles, inherent nonlinearity in experimental physical response data poses severe difficulty in empirical physical formula (EPF) construction. In this paper, we applied a novel method (namely layered feedforward neural network (LFNN) approach) to produce explicit nonlinear EPFs for experimental nonlinear electro-optical responses of doped nematic liquid crystals (NLCs...

Quadratic nonlinear photonic crystals are materials in which the second order susceptibility is spatially modulated while the linear susceptibility remains constant. These structures are significantly different than the more common photonic crystals, in which the linear susceptibility is modulated. Nonlinear processes in nonlinear photonic crystals are governed by the phase matching requirement...

There are a variety of nonlinear optical effects including higher harmonic generations, photovoltaic effects, and nonlinear Kerr rotations. They are realized by strong light irradiation to materials that results in nonlinear polarizations in the electric field. These are of great importance in studying the physics of excited states of the system as well as for applications to optical devices an...