– We have derived the local electric field inside graded metal-dielectric composite films with weak nonlinearity analytically, which further yields the effective linear dielectric constant and third-order nonlinear susceptibility of the graded structures. As a result, the composition-dependent gradation can produce a broad resonant plasmon band in the optical region, resulting in a large enhanc...

thin films of polymer doped with nonlinear optical organic dye, disperse red 1, at thickness of 1 to 2 micrometers, were prepared and studied. in order to induce an axial and orientational alignment of dye molecules within polymer matrix, a contact electric field poling was used. by this process the inherent inversion symmetry in the polymer matrix was eliminated to achieve the desired macrosco...

We investigate the nonlinear optical response of a noble metal surface. We derive the components of the third-order nonlinear susceptibility and determine an absolute value of χ((3))≈0.2 nm(2) V(-2), a value that is more than two orders of magnitude larger than the values found for typical nonlinear laser crystals. Using nonlinear four-wave mixing (4WM) with incident laser pulses of frequencies...

We have investigated the optical response of superradiant atoms, which undergoes three different damping mechanisms: radiative dissipation (γr), dephasing (γd), and nonradiative dissipation (γn). Whereas the roles of γd and γn are equivalent in the linear susceptibility χ , the third-order nonlinear susceptibility χ drastically depends on the ratio of γd and γn: When γd ≪ γn, χ (3) is essential...

Linear and nonlinear interactions of an electromagnetic wave with molecules of an isotropic medium induce in them multipole moments which contribute to electric polarization of the system [1]. Out of absorption bands optical rectification (OR) via the second-order susceptibility is forbidden but the fourth-order dipolar electric nonlinearity may cause OR in chiral liquids [2]. However, in absor...

Polyurethane closed cell (PUCC)/SiO2 nanocomposites have been prepared by using in situ polymerization approach. The third-order optical nonlinearities of PUCC/SiO2 nanocomposites, dissolved in DMF are characterized by Z-scan technique at the measurement wavelength of 532 nm. The nonlinear refractive (NLR) indices and nonlinear absorption (NLA) coefficients of samples were calculated from close...

We present experimental results on the observation of a bulk second-order nonlinear susceptibility, derived from both free-space and integrated measurements, in silicon nitride. Phase-matching is achieved through dispersion engineering of the waveguide cross-section, independently revealing multiple components of the nonlinear susceptibility, namely χ(2) yyy = 0.14 ± 0.08 ...

An enhanced method is developed for analysis of third-order nonlinearities in optical nanostructures with a scalar magnetic field frequency-domain formulation; it is shown to produce fast and accurate results for 2D problems without a superfluous vector electric field formalism. While a standard TM representation using cubic nonlinear susceptibility results in an intractable implicit equation, ...