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Holographic Gratings (holographic + grating)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Cover Picture: TiO2 Nanoparticle,Photopolymer Composites for Volume Holographic Recording (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2005
Mater.
Abstract TiO2 nanoparticle,photopolymer composites have been employed for volume holographic recording, as reported by Sánchez and co-workers on p.,1623. Photoinduced segregation of the high refractive index, grafted nanoparticles between polymer-rich areas leads to improved refractive-index modulation amplitudes with respect to the base material without nanoparticles. The cover schematically shows a holographic grating registered in this nanocomposite material. These nanocomposite materials should enable the production of holographic optical elements to efficiently control light with angle and wavelength selectivity. This could be used, for example, in liquid-crystal display technology. A new and efficient photopolymer for the recording of volume holograms is presented. The material comprises a mixture of UV-sensitive acrylates and grafted titanium dioxide nanoparticles with an average size of 4,nm. We report the formation of holographic gratings with refractive-index modulation amplitudes of up to 15.5,×,10,3,an improvement of more than a factor of four over the base material without nanoparticles,while maintaining a low level of scattering and a high transparency in the visible-wavelength range. The influence of the composition of the acrylate system on the final properties of the holographic material is also investigated and discussed. The presence of multifunctional monomers favors the compositional segregation of the different components, while the addition of monofunctional acrylate, highly compatible with the grafting of the nanoparticles, favors the dilution of these nanoparticles. [source]

Rewritable Holographic Structures Formed in Organic,Inorganic Hybrid Materials by Photothermal Processing

ADVANCED FUNCTIONAL MATERIALS, Issue 16 2009
Hiroshi Kakiuchida
Abstract Holographic and direct-written structures are fabricated in tin-doped silicophosphite thin plates containing rhodamine 6G dye by a photothermal process based on the principle of glass softening/frozen-in behavior. To be highly processable by photothermal treatment and stable at room temperature after processing, the intrinsic viscoelastic property is improved by increasing the crosslinking density of the network structure, and the photothermal conditions for efficient transfer of the irradiated photons to thermal phonons are explored. Then, the excellent rewritability and reliability of the fine processed structure are found by examining the writing/erasing repetition. Furthermore, the origins of the changes in refractive index due to photothermal treatment are classified into density change and photobleaching, and the dynamics of the formation process of holographic gratings are studied by measuring refractive index changes as functions of irradiation time and wavelength. As a result, it is found that the holographic structure consists of spatial modulation of the refractive index and the refractive index change results primarily from the change in the frozen structure, although there is a slight influence by photobleaching. [source]

Synthesis of Luminescent ZrO2:Eu3+ Nanoparticles and Their Holographic Sub-Micrometer Patterning in Polymer Composites

ADVANCED FUNCTIONAL MATERIALS, Issue 11 2009
Tsedev Ninjbadgar
Abstract Here, the facile synthesis of fluorescent ZrO2:Eu3+ nanoparticles with luminescence quantum yield of up to 8.7% that can be easily dispersed in organic solvents and utilized for the preparation of organic/inorganic volume holographic gratings is presented. The nanoparticles are prepared through a one-step solvothermal process resulting in spherical particles with a mean size of 4,nm that were highly crystalline directly after the synthesis, without any need for calcination treatment. Detailed luminescence studies of the nanoparticles as a function of Eu3+ content demonstrate that the dopant concentration and its site symmetry play an important role in the emissive properties and lifetime of the luminescent centers. It is shown that the luminescence quantum yield of the colloidal ZrO2:Eu3+ nanoparticles increases with dopant concentration up to a critical concentration of 11 mol% while the luminescence lifetime is shortened from 1.8 to 1.4 ms. Holographic photopolymerization of suitable monomer mixtures containing the luminescent nanoparticles demonstrated the ability to inscribe volume Bragg gratings (refractive index contrast n1 up to 0.011) with light-emissive properties, evidencing the high suitability of this approach for the fabrication of tailored nanomaterials for elaborate and demanding applications. [source]

Cover Picture: TiO2 Nanoparticle,Photopolymer Composites for Volume Holographic Recording (Adv. Funct.

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2005
Mater.
Abstract TiO2 nanoparticle,photopolymer composites have been employed for volume holographic recording, as reported by Sánchez and co-workers on p.,1623. Photoinduced segregation of the high refractive index, grafted nanoparticles between polymer-rich areas leads to improved refractive-index modulation amplitudes with respect to the base material without nanoparticles. The cover schematically shows a holographic grating registered in this nanocomposite material. These nanocomposite materials should enable the production of holographic optical elements to efficiently control light with angle and wavelength selectivity. This could be used, for example, in liquid-crystal display technology. A new and efficient photopolymer for the recording of volume holograms is presented. The material comprises a mixture of UV-sensitive acrylates and grafted titanium dioxide nanoparticles with an average size of 4,nm. We report the formation of holographic gratings with refractive-index modulation amplitudes of up to 15.5,×,10,3,an improvement of more than a factor of four over the base material without nanoparticles,while maintaining a low level of scattering and a high transparency in the visible-wavelength range. The influence of the composition of the acrylate system on the final properties of the holographic material is also investigated and discussed. The presence of multifunctional monomers favors the compositional segregation of the different components, while the addition of monofunctional acrylate, highly compatible with the grafting of the nanoparticles, favors the dilution of these nanoparticles. [source]

Superior-Performance Polymeric Composite Materials for High-Density Optical Data Storage,

ADVANCED MATERIALS, Issue 5 2009
Riccardo Castagna
High-resolution holographic gratings are obtained using a combination of a multifunctional acrylate (DPHP/HA), a low-molecular-weight glass-forming liquid epoxy-aromatic resin (TPMTGE), and a UV-photoinitiator (Irgacure 819). Their optical properties (sensitivity, transparency, and optical shrinkage) are promising for high-density optical data storage applications. [source]

Fabrication of transmission holographic gratings with spiroorthoester and trimethylolpropane triacrylate

POLYMER INTERNATIONAL, Issue 5 2007
Ze Li
Abstract Spiroorthoester function was found to be polymerizable with visible laser light (, = 532 nm) in the presence of diphenyliodonium hexafluorophosphate and 3,3,-carbonylbis(7-diethylaminocoumarin), as evidenced using Fourier transform infrared spectroscopy. High-performance holographic gratings were fabricated using siloxane-containing bis(spiroorthoester) compounds together with trimethylolpropane triacrylate. The volume shrinkage of the grating thus formed was much lower than that prepared with bis(glycidyl) compounds. Copyright © 2006 Society of Chemical Industry [source]