Dispersion, as the characteristic variation of refractive index with wavelength, is more pronounced, where the wavelength is approaching to the absorption band. In ultra-Optical glasses, the nonlinear refractive index, concerning to the light intensity dependent phenomenon, becomes considerable. Here, two ultra-Optical property glass systems; TiO2-Bi2O3-PbO (TBP) and Ga2O3-Bi2O3-PbO (GBP), which exhibited the most refractive indices, were selected. Their refractive index and dispersion measurements were done by `Minimum angle of deviation in a prism` method employing a spectrometer under different light spectra transmission. The corresponding nonlinear refractive indices of glasses were calculated by the Weber, et al., and Boling, et al., formulae and were analysed. The minimum refractive index in very long waves (infra-red), `n∞ ` and λ s were estimated by `Kordes semi-empirical formula` and the dispersion curve fit method. Results suggested that the both glass systems could be good candidates for use in nonlinear Optical applications, e. g. switches in all-Optical telecommunications.

We study the interaction of electromagnetic field with two of the most tunable nanostructure geometries for nanoplasmonics including the magneto-Optical nanoshell structure and the spheroidal geometry. We investigate the effect of combining both geometry and magneto-Optical properties within the same nanostructure on the field enhancement factor and Optical bistability behaviors. Since the coupling between the inner and outer surface plasmons of the nanoshell is stronger for the elongated spheroidal geometry as compared to that for the spherical case, field enhancement in ellipsoid nanoparticles is much more saleintiant. Moreover, the plasmonic field enhancement is four orders of magnitude larger for the spheroidal nanoshells as compared to spherical nanoshells. In addition to the appearance of Optical bistability in this system, it is found that the threshold and window of bistability are strongly dependent on magneto-Optical properties and geometry of the core– shell nanoparticle.

One of the most important issues in controller design and analysis of a nonlinear system is its degree of nonlinearity. Helbig et al. proposed a method in which the system, along with a linear reference model (which is the sum of a couple of first order transfer functions), is stimulated with a set of input patterns. The outputs of these systems are then compared and the nonlinearity measure of the system is obtained as the normalized difference between the outputs of these two systems. In this paper, the linear reference model is replaced with two simpler linear ones. The proposed method has been used for assessment of the nonlinearity measure of various nonlinear systems that are used as standard benchmarks by the nonlinear process control research community. The results show that, despite the use of this simpler model with less parameters, the calculated nonlinearity measure is almost similar to the one obtained by Helbig's method. Furthermore, the nonlinearity measure obtained by the proposed method can be calculated very much faster.