A series of symmetrical and unsymmetrical phenylene-vinylene （PV） based chro- mophores with the molecular configuration of donor-π-donor （D-g-D） were prepared and characterized. Iodine was first introduced into t...A series of symmetrical and unsymmetrical phenylene-vinylene （PV） based chro- mophores with the molecular configuration of donor-π-donor （D-g-D） were prepared and characterized. Iodine was first introduced into the Jr-conjugation backbone of the PV based chromophores in order to study the heavy atom effect on their linear absorption, two-photon absorption （TPA） properties, as well as singlet oxygen generation properties. TPA cross-sections of these chromophores were investigated by using the two-photon excited fluorescence method. The unsymmetrical chromophores were found to have larger TPA cross-section values compared to their symmetrical counterparts. For one of the unsymmetrical chromophores with the iodine incorporation, a large TPA cross section value with quenched emission was found. The decreased fluorescence quantum yield of a molecule can be ascribed to the increased intersystem crossing, which is favorable for enhancing the singlet oxygen generation. Therefore, the unsymmetrical PV based chromophores with heavy atom incorporation are promising singlet oxygen sensitizers for the photodynamic therapy application.展开更多
This letter reports the influence of branches and bromine substitution of the photosensitizers on one-and two-photon absorption generation of singlet oxygen.Near-infrared femtosecond Ti:squassier laser was utilized to...This letter reports the influence of branches and bromine substitution of the photosensitizers on one-and two-photon absorption generation of singlet oxygen.Near-infrared femtosecond Ti:squassier laser was utilized to determine two-photon properties of the photosensitizers tuning wavelength from 700 to 880 nm at intervals of 20 nm.One-and two-photon optical and photophysical properties of the photosensitizers show significant dependence on the branches and substituted bromine atoms.展开更多
H_5 photonic crystal（PC） microcavities co-implanted with erbium（Er） and oxygen（O） ions were fabricated on silicon-on-insulator（SOI） wafers.Photoluminescence（PL） measurements were taken at room temperature an...H_5 photonic crystal（PC） microcavities co-implanted with erbium（Er） and oxygen（O） ions were fabricated on silicon-on-insulator（SOI） wafers.Photoluminescence（PL） measurements were taken at room temperature and a light extraction enhancement of up to 12 was obtained at 1.54μm,as compared to an identically implanted unpatterned SOI wafer.In addition,we also explored the adjustment of cavity modes by changing the structural parameters of the PC,and the measured results showed that the cavity-resonant peaks shifted towards shorter wavelengths as the radius of the air holes increased,which is consistent with the theoretical simulation.展开更多
基金National Natural Science Foundation of China(21102144)in part supported by 100 Talents Programme of Chinese Academy of Sciences
文摘A series of symmetrical and unsymmetrical phenylene-vinylene （PV） based chro- mophores with the molecular configuration of donor-π-donor （D-g-D） were prepared and characterized. Iodine was first introduced into the Jr-conjugation backbone of the PV based chromophores in order to study the heavy atom effect on their linear absorption, two-photon absorption （TPA） properties, as well as singlet oxygen generation properties. TPA cross-sections of these chromophores were investigated by using the two-photon excited fluorescence method. The unsymmetrical chromophores were found to have larger TPA cross-section values compared to their symmetrical counterparts. For one of the unsymmetrical chromophores with the iodine incorporation, a large TPA cross section value with quenched emission was found. The decreased fluorescence quantum yield of a molecule can be ascribed to the increased intersystem crossing, which is favorable for enhancing the singlet oxygen generation. Therefore, the unsymmetrical PV based chromophores with heavy atom incorporation are promising singlet oxygen sensitizers for the photodynamic therapy application.
基金supported by the National Natural Science Foundation of China (20776165,20702065,20872184)the Fundamental Research Funds for the Central Universities (CDJZR10220006)+1 种基金Chongqing Natural Science Foundations (CSTC2012jjB50007)Fang Gao appreciates warm encouragements from the Program of New Century Excellent Talents in University (NCET-10-0876)
文摘This letter reports the influence of branches and bromine substitution of the photosensitizers on one-and two-photon absorption generation of singlet oxygen.Near-infrared femtosecond Ti:squassier laser was utilized to determine two-photon properties of the photosensitizers tuning wavelength from 700 to 880 nm at intervals of 20 nm.One-and two-photon optical and photophysical properties of the photosensitizers show significant dependence on the branches and substituted bromine atoms.
基金Project supported by the National Key Basic Research Special Fund of China(No.2007CB613404)the National High Technology Research and Development Program of China(No.2011AA010303)the National Natural Science Foundation of China(Nos.61090390, 60837001,60977045,60877014,60776057)
文摘H_5 photonic crystal（PC） microcavities co-implanted with erbium（Er） and oxygen（O） ions were fabricated on silicon-on-insulator（SOI） wafers.Photoluminescence（PL） measurements were taken at room temperature and a light extraction enhancement of up to 12 was obtained at 1.54μm,as compared to an identically implanted unpatterned SOI wafer.In addition,we also explored the adjustment of cavity modes by changing the structural parameters of the PC,and the measured results showed that the cavity-resonant peaks shifted towards shorter wavelengths as the radius of the air holes increased,which is consistent with the theoretical simulation.
