Nonlinear absorption

Finally, in Section IV dithiolene complexes with interesting optical properties, such as strong near-IR (NIR) absorption, nonlinear optical behavior, and the use of some dithiolene complexes for optical data storage will be reviewed. In Section V, attempts toward coupling conducting, and magnetic or optical properties will be discussed briefly. 

Overall, the LMCT absorptions conform to expectation based on Eq. 9, but the effective values of Xp are smaller than those for IPCT absorptions. Nonlinear covalent effects in appear to be relatively small. 

Keywords two-photon absorption three-photon absorption multi-photon absorption nonlinear... 

Variable absorption Nonlinear kinetics Induction of cytochrome P450s Zero-order kinetic of elimination ° Side effects ... 

The nonlinear nanolayered materials are fabricated by introducing nonlinear dyes into alternate layers of the nanolayered polymer. Nonlinear dyes with large refractive and absorptive nonlinearities have designed, synthesized, and characterized at NRL over the past several years. The nonlinear optical chromophore is typically a phthalocyanine. Polymer miscibility was achieved by peripheral substitution of the phthalocyanine. Nonlinear dyes compatible with styrenes, epoxies, (19,20) and urethane polymers (21) are available. 

Keywords Cubic nonlinearity. Molecular switches, Nonlinear absorption. Nonlinear refraction... 

General optical Refractive index Two-photon absorption Nonlinear dielectric... 

Although the two-color Z-scan can separate the refractive and absorptive nonlinear contributions, it is not capable of distinguishing between ultrafast (i.e., electronic) and cumulative (i.e., thermal effects) nonlinearities. However, with the introduction of a time delay between the probe and excitation beams of a two-color Z-scan apparatus it is possible to discern nonlinear effects having different temporal responses [25]. 

The coefficients x are applied for the description of the macroscopic susceptibilities instead of the molecular coefficients a, p, and y. The first-order susceptibility x describes linear processes such as refraction and absorption. Nonlinearities are characterized by the susceptibilities of higher order (x , x - ) The even- and odd-order terms lead to different nonlinear responses, is contributed to the polarization only in noncentrosymmetric media, and x contributing in any media irrespective of the symmetry (Prasad and Wilhams, 1991). 

The CA Z-scan curves taken for solutions (see Figure 22.21a) are typical for a material with a negative nonlinear refractive index. The nonlinear absorption was too small to be detected here because the observation of absorptive nonlinearities generally requires nearly excitonic resonance in CdS NP solutions [75,76]. The Kerr (or nonlinear refractive) index, 2, was calculated to be approximately -2x 10 m W at a peak irradiance of 320 MW cm for... 

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