Nonlinear Optical Properties Of Samples Research Articles

Linear and nonlinear optical properties of Al2O3/Y2O3 nanolaminates fabricated by atomic layer deposition

The structure and composition of nanocomposites constitute design parameters that can be manipulated to get control over their linear and nonlinear optical response. In this work, we report the linear and nonlinear optical properties of samples consisting of multiple Al2O3/Y2O3 bilayers with a total thickness of ∼ 500 nm, fabricated through the atomic layer deposition technique onto Si and SiO2 substrates. Fabrication of the multiple layer configurations was made for four Y2O3 layer thicknesses, while maintaining a constant Al2O3 layer thickness for all the samples fabricated. Physical and chemical characterization of the samples produced was conducted by optical ellipsometry, transmission electron microscopy and XRD. Moreover, their third-order nonlinear optical properties were studied through the z-scan technique with 100 fs pulses at 800 nm from a Ti:Sapphire laser, allowing the resolution of the refractive and absorptive contributions to the response. The nonlinear parameters extracted from the experiments are discussed in terms of the fabrication thickness of the selected materials. Additionally, figures of merit relevant for the possible application of these materials in optical processing system are calculated and discussed.

Polarity effects on the optical responses of some biologically active molecules with different substituents

Environment polarity characteristics of biomolecules as an important factor can enhance their optical behaviors. Hence, knowledge of environment polarity effects can give valuable information about the function of molecules in different phenomena. In this work, linear, first, and second-order hyperpolarizability of (E)-2-benzylidene-2,3-dihydro-5,6-dimethoxyinden-1-one as pharmacologically important compounds were studied in different environments. The analysis was done by using environment multi-parameter polarity parameters. According to the results, environment polarity has different effects on the linear and nonlinear optical properties of samples. A quantitative study indicated that general solvent effects play important roles in molecular linear behaviors. Furthermore, environments with strong hydrogen bond acceptor ability increase molecular nonlinearity. On the other hand, environment polarity indicated the same effects on the molecular first and second-order nonlinearity. In this case, the studies on the molecular first-order nonlinearity in different solvents can give valuable information about environment effects on the molecular higher-order nonlinearity.

Third-order nonlinear optical properties of a multi-layer Al2O3/ZnO for nonlinear optical waveguides.

This is a report of a study of the nonlinear optical properties of samples based on multiple Al2O3/ZnO bilayers fabricated by atomic layer deposition (ALD) in silica. The multi-layer configuration for samples consists of alternated layers of constant thickness of Al2O3 (Δx) and ZnO (Δy) nanolaminates with a total thickness of ∼ 500 nm. The physical properties of the samples were characterized by means of TEM, spectrophotometry and variable angle spectroscopic ellipsometry. The absorptive and refractive contributions to the nonlinearity of the samples were studied by means of z-scan technique using a 100 fs at 800 nm. The nonlinear parameters, β and n2, are studied using different values of the layers thickness, Δx and Δy, in the nanolaminated stack. The possible applications in optical signal processing system are discussed by means of the figures of merit W and T.

Metalloporphyrin bonded SiO2 organic-inorganic materials and their strong nonlinear refractive index

Copper metalloporphyrin was bonded to 3-aminopropltriethoxysilane (NH2(CH2)3Si(OC2H5)3, KH550) by the chemical reaction between the carboxyl group of Cu(Ⅱ) meso-Tertra(4-carboxyphenyl)porphine (Cu(Ⅱ)-TCPP) and amino-group of KH550. The copper metalloporphyrin was connected to gel network after the hydrolysis and condensation of the product. The reaction product of different concentrations was hybridized with 3-glycidoxypropltrimethoxysilane (CH2OCHCH2O(CH2)3Si(OCH3)3, KH560) with sol-gel processing to form sol-gel inorganic material, which has good physical-chemical and optical properties. The cross-linkage of Cu(Ⅱ)-TCPP and KH550 was estimated and confirmed with FT-IR spectroscopy. The state of metalloporphyrin molecules was investiaged by UV/VIS spectra. It was found that the Cu(Ⅱ)-TCPP exists mainly in the state of monomer. Nonlinear optical properties of samples was studied by Z-scan technique using Ti:Sapphire femto-second laser pluses. The nonlinear refractive index n2 reached -1.1161×10-16 m2/W.