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Title: Dielectric characteristic of photoinduced isomerization in azo-dye doped polymeric matrices

Abstract

The dielectric permittivities and losses of poly(methyl methacrylate) doped with different concentrations of azo dye are investigated under the irradiation of 532 nm light for the first time. The dielectric permittivities increase with the concentration of chromophores increasing, and the dielectric relaxation is mainly influenced by the doped azo-dye chromophores. Given the dye concentration, the dielectric permittivities depend on the pump power of 532 nm light. With the increase of pumping light power, the low frequency dielectric losses increase while the high frequency dielectric losses decrease. The results are explained based on the photoinduced isomerization of chromophores and the interaction between the chromophores and polymer matrices.

Authors:
;  [1];  [2]
  1. Department of Physics, East China University of Science and Technology, 130 Meilong Road, Box 385, Shanghai 200237 (China)
  2. (China)
Publication Date:
OSTI Identifier:
20779217
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 88; Journal Issue: 18; Other Information: DOI: 10.1063/1.2200390; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AZO DYES; DIELECTRIC MATERIALS; DOPED MATERIALS; IRRADIATION; ISOMERIZATION; METHACRYLIC ACID ESTERS; PERMITTIVITY; POLYMERS; RELAXATION

Citation Formats

Luo Duanbin, Deng Li, and Key Laboratory of Optical and Magnetic Resonance Spectroscopy, East China Normal University, Ministry of Education, Shanghai 200062. Dielectric characteristic of photoinduced isomerization in azo-dye doped polymeric matrices. United States: N. p., 2006. Web. doi:10.1063/1.2200390.
Luo Duanbin, Deng Li, & Key Laboratory of Optical and Magnetic Resonance Spectroscopy, East China Normal University, Ministry of Education, Shanghai 200062. Dielectric characteristic of photoinduced isomerization in azo-dye doped polymeric matrices. United States. doi:10.1063/1.2200390.
Luo Duanbin, Deng Li, and Key Laboratory of Optical and Magnetic Resonance Spectroscopy, East China Normal University, Ministry of Education, Shanghai 200062. Mon . "Dielectric characteristic of photoinduced isomerization in azo-dye doped polymeric matrices". United States. doi:10.1063/1.2200390.
@article{osti_20779217,
title = {Dielectric characteristic of photoinduced isomerization in azo-dye doped polymeric matrices},
author = {Luo Duanbin and Deng Li and Key Laboratory of Optical and Magnetic Resonance Spectroscopy, East China Normal University, Ministry of Education, Shanghai 200062},
abstractNote = {The dielectric permittivities and losses of poly(methyl methacrylate) doped with different concentrations of azo dye are investigated under the irradiation of 532 nm light for the first time. The dielectric permittivities increase with the concentration of chromophores increasing, and the dielectric relaxation is mainly influenced by the doped azo-dye chromophores. Given the dye concentration, the dielectric permittivities depend on the pump power of 532 nm light. With the increase of pumping light power, the low frequency dielectric losses increase while the high frequency dielectric losses decrease. The results are explained based on the photoinduced isomerization of chromophores and the interaction between the chromophores and polymer matrices.},
doi = {10.1063/1.2200390},
journal = {Applied Physics Letters},
number = 18,
volume = 88,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2006},
month = {Mon May 01 00:00:00 EDT 2006}
}
  • We report the generation of dark spatial solitons in bulk Disperse Red 1 doped poly(methyl methacrylate) using photoinduced reorientation of azo-dye molecules. Planar solitions are formed when illuminated with a continuous-wave laser at intensities of the order of hundreds of miliwatts per square centimeter. The width of the soliton saturates to a minimum value at high intensity; and when the width of the initial dark notch is reduced, the equilibrium minimum width is unchanged.
  • We describe the spontaneous photoinduced patterning of azo-dye polymer films. We have observed that the illumination of an azo-dye polymer film by a uniform single laser beam with normal incidence leads to a self-structurization process that results in the formation of well-ordered submicrometer-sized structures whose organization depends on the light polarization direction. A modulation depth as high as 100 nm can be achieved. The influence of several experimental parameters on the structure formation is studied. Results are discussed and confronted to different models and phenomena already investigated in the literature. A physical origin to this peculiar photopatterning process is proposed.
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  • The photoexcitation of 4-(dicyanomethylene)-2-methyl-6-(p-(dimethylamino)styryl)-4H-pyran (DCM) induces a large intramolecular charge transfer (ICT) from the dimethylamino electron-donor group to the dicyanomethylene acceptor group. The dramatic effect of the solvent polarity on the absorption and fluorescence spectra on the one hand and the competition between the nonradiative S{sub 1} {yields} S{sub 0} deactivation and trans {yields} cis isomerization processes on the other hand has been examined. Our results clearly show that DCM isomerization efficiency is very low in the more polar solvents. The S{sub 1} {yields} S{sub 0} internal conversion may intervene at a torsional angle smaller than 90{degree} before reaching themore » perpendicular configuration.« less