Study of surface relief gratings on azo organometallic films in picosecond regime

Materials for optical data storage and optical information processing must exhibit good holographic properties. Many materials for these applications have been already proposed. Here we describe a grating inscription process characterized by short inscription time and long-time stability. A series of ruthenium-acetylide organometallic complexes containing an azobenzene fragment were synthesized. Photo-induced gratings were produced by short pulse (16 ps, 532 nm) laser irradiation. The surface relief gratings formed at the same time were observed by atomic force microscope. In this work, we highlight the short inscription times brought into play as well as the good temporal stability of these gratings stored at room temperature. We study the influence of the polarization states and the light intensity of writing beams on the dynamics of the surface relief gratings formation and we compare these results with those of a known representative of azobenzene derivative (Disperse Red 1). Lastly, we show that it is possible to write two-dimensional surface relief gratings

Azo-azulene derivatives for nonlinear optical applications

Organic materials are of high interest and are widely used for the development of new powerful and low dimensional technologies. They exhibit several advantages with respect to inorganic compounds such as large cubic and quadratic optical nonlinearities, flexibility, easy manufacturing and so on. Among them, some present abilities for photonic or nonlinear optical applications. Intensive researches have been performed these latest decades to synthesize highly efficient and optically active molecules because of the miniaturization of optoelectronic devices. Azo-azulene derivatives are an interesting class of organic molecules for potential applications in optoelectronics and optical data storage due to their polyfunctional properties. We discuss second and third order nonlinear optical properties of a series of azo-azulene compounds in solid state. Thin films were prepared by incorporating these molecules in a polymethylmetacrylate (PMMA) matrix and were investigated. Moreover, potential usage of these guest-host systems for optical data storage is also discussed

Non-linear optical and electrical properties of ZnO doped Ni Thin Films obtained using spray ultrasonic technique

In the present study zinc oxide doped Nickel thin films (ZnO:Ni) were deposited on glass substrates using a chemical spray ultrasonic technique. The effect of Ni concentration on the structural, electrical, optical, and non-linear optical (NLO) properties of the ZnO:Ni thin films was investigated. The films were analyzed using X-ray diffraction (XRD), profilometry and optical transmittance. A polycrystalline structure with a preferential growth along the ZnO (002) plane was found, the optical transmittance was found to be higher than 80% and the band gap (E(g)) varied from 3.19 to 3.27 eV. The value of the electrical conductivity was found. Moreover, the effective non-linear quadratic and cubic electronic susceptibilities of thin film samples were determined by the SHG and THG techniques, working at 1064 nm. (C) 2011 Elsevier B.V. All rights reserved

Nonlinear optical properties of selected natural pigments extracted from spinach: Carotenoids

They are report here, for the first time in authors knowledge, results on third order nonlinear optical susceptibilities from a series of natural pigments extracted from spinach. The measurements were performed in-situ at 532 nm wavelength using degenerate four wave mixing technique (DFWM). For comparison third order nonlinear optical susceptibilities of the same pigments were also evaluated using third harmonic generation (THG) set up at 1064 nm. The electronic contribution to the observed properties was also deduced. The measurements were performed on thin films deposited on a thick glass substrate. These pigments were also identified by UV–VIS spectral analysis. All these results were in good agreement with the literature data

1-[3-(4-Nitro­phen­yl)propano­yl]urea acetic acid monosolvate

The title compound, C10H11N3O4·C2H4O2, was prepared by an electrochemical technique. In the crystal, acetic acid mol­ecules are involved in hydrogen bonding to two separate propano­ylurea mol­ecules, acting as a donor in an O—H⋯O inter­action and as an acceptor in two N—H⋯O inter­actions. The propano­ylurea mol­ecules inter­act with each other via N—H⋯O hydrogen bonds. C—H⋯O inter­actions also stabilize the crystal structure

Synthesis growth and optical properties of semi organic non linear optical single crystal

A new and efficient semi organic nonlinear optical crystal from the amino acid family has been grown by slow evaporation technique from aqueous solution. The crystals structures were solved by direct methods using SIR92 (WINGX) and refined by a full matrix least-square method using SHELXL97. All this compounds crystallized in noncentrosymetric groups. Second harmonic generation measurements were performed by applying the Kurtz and Perry model, to powder samples of compounds at 1,064 nm

Investigation study on the nonlinear optical properties of natural dyes: Chlorophyll a and b

We report the results on third and second order nonlinear optical susceptibilities of two natural pigments extracted from spinach. The last were identified by UV-vis spectral analysis. Thin films were prepared by spin coating technique and deposited on glass substrate. The measurements of third order nonlinear optical susceptibilities were performed in solutions using degenerate four wave mixing technique (DFWM) at measurement wavelength of 532 nm. The third and second order nonlinear optical susceptibilities of the studied pigments were also evaluated on thin films using the third and second harmonics generation (THG and SHG) Maker fringes technique respectively at 1064 nm. All these results were in good agreement with the literature data

Influence of Bi doping on the electrical and optical properties of ZnO thin films Superlattices and Microstructures

Transparent conducting ZnO doped Bi thin films were prepared on glass substrates by ultrasonic spray method. The influence of Bi doping concentration on the structural, optical and nonlinear optical properties of ZnO thin films was studied. The X-ray diffraction (XRD) analysis show that all studied films have a hexagonal wurtzite structure and are preferentially oriented along the c-axis from substrate surface. Optical transmittance measurements show that all samples have average 80% transparency in the visible light. Optical band gap values range between 3.14 and 3.28 eV. ZnO film with 3 wt% of Bi showed the highest electrical conductivity. In addition, the second and third order nonlinear susceptibilities were determined and their values have been calculated

Correlation between structural studies and third order NLO properties of selected new quinolinium semi-organic compounds

New quinolinium semi-organic compounds of formula ( C 9 H 8 N ) 2 + · SO 4 2 - , H 2 O (I) (bis-quinolinium sulphate monohydrate) and ( C 9 H 8 N ) + · NO 3 - (II) (quinolinium nitrate) have been synthesized and characterized by UV–Vis absorption spectroscopy, nonlinear optical (NLO) measurements and by single crystal X-ray diffraction. The third order nonlinear optical properties of (I) and (II) were investigated using two methods: the degenerate four wave mixing technique (DFWM) performed in solution at λ = 532 nm and the third-harmonic generation (THG) measurements carried out on thin films at λ = 1064 nm. The NLO measurements showed that compound (I) presents better nonlinear optical properties compared to compound (II). To understand further the optical behaviour of (I) and (II), the crystal structures of both compounds were determined from accurate single crystal X-ray diffraction measurements performed at 100 K. The crystallographic studies revealed the key role of the intermolecular interactions and the molecular arrangements in the enhancement of the NLO properties

Hydrogen bonding in cytosinium dihydrogen phosphite

In the title compound, C4H8N3O4P+·H2PO3 −, the cytosine mol­ecule is monoprotonated and the phospho­ric acid is in the monoionized state. Strong hydrogen bonds, dominated by N—H⋯O inter­actions, are responsible for cohesion between the organic and inorganic layers and maintain the stability of this structure