The bound electronic nonlinear refractive index, n 2 • and two-photon absorption (2PA) coefficient, 6, are measured in a variety of inorganic dielectric solids at the four harmonics of the Nd:YAG laser using Z scan. The specific materials studied are: barium fluoride (BaF2 ), calcite (CaC03), potassium bromide (KBr), lithium fluoride (LiF), magnesium fluoride (MgFz), sapphire (Ab03), a tellurit...

All optical switching (AOS) applications require materials with a large nonlinear refractive index (n2) but relatively small linear and nonlinear absorption loss. The figure-of-merit (FOM), defined as the ratio between the real and imaginary parts of the second hyperpolarizability (γ), is widely used to evaluate the operating efficiency of AOS materials. By using an essential-state model, we de...

this paper focuses on the optimization of initiating dimensions of groove bearing in association with de- sired design of vehicle’s front structure which is made up of low carbon steels in the case of frontal collision. axial bearing analysis is done numerically using nonlinear finite element code ls-dyna. in this analysis, changes of two main parameters including measure of energy absorption o...

In medical diagnostic ultrasound (US), higher than-in-water nonlinearity of body fluids and tissue usually does not produce strong nonlinearly distorted waves because of the high absorption. The relative influence of absorption and nonlinearity can be characterized by the Gol'dberg number Gamma. There are two limiting cases in nonlinear acoustics: weak waves (Gamma < 1) or strong waves (Gamma >...

The bound electronic nonlinear refractive index, n 2 • and two-photon absorption (2PA) coefficient, 6, are measured in a variety of inorganic dielectric solids at the four harmonics of the Nd:YAG laser using Z scan. The specific materials studied are: barium fluoride (BaF2 ), calcite (CaC03), potassium bromide (KBr), lithium fluoride (LiF), magnesium fluoride (MgFz), sapphire (Ab03), a tellurit...

Plasmonics, which are based on the collective oscillation of electrons due to light excitation, involve strongly enhanced local electric fields and thus have potential applications in nonlinear optics, which requires extraordinary optical intensity. One of the most studied nonlinearities in plasmonics is nonlinear absorption, including saturation and reverse saturation behaviors. Although scatt...

An investigation of the nonlinear absorption of a wide range of structurally diverse porphyrin monomers, bisporphyrins and trisporphyrins, using open Z-scan technique with 6 ns pulsed laser operating at 532 nm was carried out. Using the theory of reverse saturable absorption, the intensity dependent nonlinear absorption coefficient eff was deduced from the experiments. Monomers which Soret band...

A method of evaluating the thermal focal length of nonlinear crystal via transmission spectrum of a swept cavity (TSSC) is presented. By recording the resonant point offset of the TSSC, the thermal focal length can be successfully measured. Furtherly, by distinguishing the absorption of ultraviolet (UV) laser and UV laser induced infrared absorption (ULIIRA), it is clear that the ULIIRA is the ...

A theoretical study of parametric processes near the electron cyclotron resonance region in tokamak plasmas is presented. Parametric dispersion relations, including finite wave length of the driver pump, of principal and harmonic parametric excitations, are given. The problem of primary and secondary decays including their temporal and spatial growth rates is studied. In the nonlinear phase of ...