we will present a detailed investigation of intersubband transitions process in core-multi shells quantum dots. the confined wave functions and eigenenergies of electrons in quantum dots have been calculated under the effective-mass approximation by solving a three-dimensional schrodinger equation. excellent dependence is found between size effects, time relaxation and degenerate four wave mixi...

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...

We observe optical third-harmonic generation in atomically thin films of MoS2 and deduce effective third-order nonlinear susceptibilities on the order of 10(-19) m(2)/V(2), which is comparable to that of commonly used semiconductors under resonant conditions. By measuring the susceptibility as a function of light wavelength, we find significant enhancements of the susceptibility by excitonic re...

in this study, the nonlinear optical properties and optical limiting performance of the silver nanoparticles (agnps) in distilled water are investigated. the nonlinear absorption coefficient of the colloid is measured by the z-scan technique. the optical limiting behavior of the agnp suspension is investigated under exposure to nanosecond laser pulses at 532 nm. the results show that nonlinear ...

The third-order nonlinear optical properties and optical limiting studies of donor substituted hydrazone derivatives were investigated using the single beam Z-scan technique at 532nm.The calculated values of nonlinear refractive index ,third-order nonlinear optical susceptibility and second order molecular hyperpolarizability are of the order of esu 11 10 , esu 13 10 and esu 31 10 respectively....

In this study the third order nonlinear susceptibilities are theoreticallycalculated for an electron confined in an isolated PbS/ CdSe/ CdS spherical core-shellshellquantum dots. Our calculation is associated with intersubband transitions in theconduction band. We used the effective mass approximation in this study which is asimple and straightforward study of the third-order optical nonlineari...

We report on the electro-optic and nonlinear optical properties of waveguides produced by low fluence (Phi = 1.25x10(14) ions/cm(2)) H+ ion implantation in the organic nonlinear optic crystal 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium tosylate (DAST). The profile of the nonlinear optical susceptibility has been determined by measuring the reflected second-harmonic generation efficiency from ...

The optical second harmonic generation from a thin magnetic film on a nonmagnetic substrate is theoretically investigated for both sand p-polarized incident light. The contributions of lattice misfit strain as well as of misfit dislocation strain to the second-order nonlinear optical susceptibility are described using a nonlinear photoelastic tensor, together with the contribution of magnetizat...