The research on Nd 3þ doped new solid-state laser hosts with specific thermo-mechanical and optical properties is very active. Nd 3þ doped tellurite glasses are suitable for these applications. They have high linear and nonlinear refraction index, wide transmittance range. The TeO 2 -ZnO (TZO) glass considered in the present work combines all those features and the nonlinear optical properties can be used for the development of Kerr-lens mode-locked sub picosecond lasers. Recently the laser performance of Nd 3þ doped TZO glass and was reported and laser slope efficiency of 21% was observed. We investigate how the intensity variation and the silver nanoparticles codoping affects the nonlinear optical properties of Nd 3þ doped TZO glasses. Intensity dependent nonlinear refraction indices coefficients at 750, 800 and 850 nm were observed. The nonlinear optical features were obtained through ultrafast single beam zscan technique with excitations at 750, 800 and 850 nm and are up to two orders of magnitude higher than those reported in the literature.

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In this study, structural and thermal properties of dispersed carbon nanomaterials such as single-wall carbon nanotubes and graphene in water are investigated. Carbon nanostructures are dispersed in the fluid through surfactant and ultrasonication treatment. Structural studies of the samples are carried out by Raman spectroscopy which show that the dispersion process leads to the formation of two kind of nanofluids: nanostructured graphene based and single-wall carbon nanotubes ones. The first in the form of graphene dots. The thermal diffusivities of the samples are measured by thermal lens technique. Contrary to what is normally expected our nanofluids show a considerable reduction in thermal conductivity. The reduction is stronger for graphene dots than for the carbon nanotubes. This peculiar behavior of the thermal conductivity is attributed to the high concentration ratio of surfactant to dispersed particles, as well as, the formation of air layer or bubbles attached to the nanoparticles due to sonication process. To evaluate this hypothesis, simulation of the effective thermal conductivity based on Murshed model is conducted for spherical and cylindrical particles surrounded by air layer. The simulation shows an effective decrease in thermal conductivity, which corroborates with the experimental trend.

Here, we report CA Z-Scan results for 80TeO2.20ZnO:xDy3+ glasses (x =1.0,2.0mol%). Both samples presented a self-focusing lens like behavior, with a nonlinear refractive index varying from (5.87 ± 0.04)10 − 15 cm2/W to (20.37 ± 0.09)10 − 15 cm2/W.