Second-order nonlinearity in bulk azodye-doped hybrid inorganic–organic materials by nonresonant all-optical poling

Luminescence of Eu(DBM)3Phen-doped in azobenzene-containing copolymers--effects of absorption overlapping of two components

Poly(N-isopropylacrylamide)-b-poly[6-[4-(4-methylphenyl-azo)phenoxy]hexylmethacrylate] (PNIPAM(32)-b-PAzoMM(8)) and poly(N-isopropylacrylamide)-b-poly[6-[methyl(4-nitrophenyldiazenyl)phenyl]aminohexylmethacrylate] (PNIPAM(32)-b-PAzoNO(10)) were prepared by reversible addition-fragmentation chain transfer (RAFT) radical polymerization. The optical properties of Eu(DBM)(3)Phen (Eu, Europium; DBM, dibenzoylmethide; Phen, 1,10-phenanthroline)-doped azobenzene-containing copolymer vesicle solutions were studied by UV-vis and fluorescence spectroscopy. When the electronic transition bands of azobenzene and Eu(DBM)(3)Phen overlapped at about 350 nm in PNIPAM(32)-b-PAzoMM(8), the fluorescent emission intensity at 612 nm of Eu(DBM)(3)Phen could be modulated by irradiation with UV and visible light. However, when the absorption of the azobenzene-moiety red-shifted to 477 nm in PNIPAM(32)-b-PAzoNO(10), the luminescence intensity of Eu(DBM)(3)Phen was not affected any longer. The difference between these two systems was possibly caused by the energy allocation in the luminescence process, which was discussed in detail.

Photo-responsive properties of azobenzene small molecules in sol-gel hybrid TiO(2)/ormosil organic-inorganic matrices

Azodye-doped TiO(2)/ormosil hybrid materials for photonic applications were prepared by a low temperature sol-gel process from an organic-inorganic hybrid system. Acid-catalyzed solutions of gamma-glycidoxypropyltrimethoxysilane and methyltrimethoxysilane mixed with tetrapropyl orthotitanate were used as hybrid matrix precursors. The trans-cis-trans photoisomerization of azobenzene small molecules in sol-gel hybrid organic-inorganic matrices was induced by a photoirradiation with UV light and subsequent visible light. It was found that the hybrid film doped with azodyes and heated at a lower temperature was much better for applications in optical storage or optical switch. The planar waveguide properties of the hybrid films were also investigated by using a prism coupling technique. These results indicates that it is possible for the as prepared hybrid films to allow directly integrating on the same chip the optical storage or optical switch devices with the pump source.