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Photonic Materials (photonic + material)

Distribution by Scientific Domains
Polymers and Materials Science100%

Selected Abstracts

Graphene,Polymer Nanofiber Membrane for Ultrafast Photonics

ADVANCED FUNCTIONAL MATERIALS, Issue 5 2010
Qiaoliang Bao
Abstract A freestanding membrane composed of a nanofiber network of a graphene,polymer nanocomposite is fabricated by electrospinning and applied as an optical element in fiber lasers. The functionalization of graphene with conjugated organic molecules provides a handle for improving mechanical and thermal properties as well as tuning the optical properties. A small loading (0.07,wt%) of functionalized graphene enhances the total optical absorption of poly(vinyl acetate) (PVAc) by 10 times. The electrospun graphene,polymer nanocomposites exhibit wideband saturable absorbance for laser pulse shaping, and attain a larger modulation depth and smaller nonsaturable loss than single-walled carbon nanotubes. The results show that electrospun graphene nanocomposites are promising candidates as practical and efficient photonic materials for the generation of ultrashort pulses in fiber lasers. [source]

Dye-Doped POSS Solutions: Random Nanomaterials for Laser Emission

ADVANCED MATERIALS, Issue 41 2009
Angel Costela
New perspectives on disorder in photonic materials are opened up by polyhedral oligomeric silsesquioxanes (POSS) dispersed at a molecular level in dye-doped liquid and solid solutions. The optical homogeneity of these hybrid materials assures a coherent laser action, which is significantly enhanced by the stimulated emission multiply scattered by passive POSS centers. [source]

Photoluminescent Fibers: Anisotropic Self-Assembly of Photoluminescent Oligo(p -Phenylenevinylene) Derivatives in Liquid Crystals: An Effective Strategy for the Macroscopic Alignment of , -Gels (Adv. Mater.

ADVANCED MATERIALS, Issue 40 2009
40/2009)
Takashi Kato, Ayyappanpillai Ajayaghosh, and co-workers report on p. 4029 that aligned photoluminescent ,-conjugated fibers are formed through anisotropic self-assembly of oligo(p -phenylenevinylene) gelators in smectic and nematic liquid crystals. The aligned fibers exhibit polarized photoluminescent properties. These self-assembled liquid-crystalline composites may be applicable to new types of electro-optical and photonic materials. [source]

Refractive-index anisotropy and optical dispersion in films of deoxyribonucleic acid,

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2007
Anna Samoc
Abstract We have determined the refractive indices in the directions parallel and perpendicular to the surface plane of films of deoxyribonucleic acid (DNA) and their wavelength dispersion. These parameters are fundamental for understanding the properties of waveguiding structures containing DNA-based photonic materials. The orientation of DNA molecules in films and their optical properties are sensitive to the film fabrication and environmental conditions influencing the structure. Prism coupling measurements show ambient-humidity-related changes in the refractive index, birefringence, and anisotropy of the alignment of the DNA molecules in the films studied. These films were 0.5,5 ,m thick, were prepared by both spin coating and casting from aqueous solutions containing 0.1,3 wt % DNA, and were measured in ambient air with relative humidities of 37,58%. The optical properties of the films and the orientation of the DNA molecules are discussed with respect to the mechanism for the formation of the polymer liquid-crystalline phases during film deposition. The dispersion of the refractive indices in films of native DNA has been derived from interference fringes in absorption and reflection spectra in the wavelength range of 350,2700 nm through the fitting of the positions of the fringes with the Sellmeier dispersion formula in combination with the prism coupling data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 236,245, 2007 [source]