• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.3
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• pp.142-148
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• 2002

Considerable progress has been made in organic photorefractive materials, since the first observation of photorefractive phenomena from organic materials. Within recent years, a large number of organic photorefractive materials, especially amorphous materials, have been developed based on polymeric composites, fully functional polymers and the multi-functional chromophore approach. Among these organic photorefractive materials, some of them containing carbazole components as a charge transporting function have been demonstrated to exhibit high performance photorefractive effects. The carbazole building blocks with charge transporting function or multifunctions play a very important role in photorefraction. In this paper, it confirmed that acceptor-substituted carbazoles show the multifunctionality both of photoconductivity and electro-optic(EO) activity and photorefractive materials newly can be developed with acceptor-substituted carbazoles.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.120-124
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• 2002

Considerable progress has been made in organic photorefractive materials, since the first observation of photorefractive phenomena from organic materials. Within recent years, a large number of organic photorefractive materials, especially amorphous materials. have been developed based on polymeric composites, fully functional polymers and the multifunctional chromophore approach. Among these organic photorefractive materials, some of them containing carbazole components as a charge transporting function have been demonstrated to exhibit high performance photorefractive effects. The carbazole building blocks with charge transporting functionality or multifunctions play a very important role in photorefraction and have been widely used in the molecular design approach to new organic photo- refractive materials.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.938-940
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• 2014

This paper discusses a coherence-gated three-dimensional imaging system based on photorefractive holography, which was applied to imaging through turbid media with a view to developing biomedical instrumentation. A rapid response photorefractive device doped with 2,4,7-trinitro-9-fluorenylidene malononitrile was used to generate the hologram grating. The estimated depth resolution was $20{\mu}m$, which corresponds to the coherence length of the light source. In this coherence imaging system, tomographic imaging of a 3-dimensional object composed of a $50{\mu}m$ thick cylindrical layer was achieved. The proposed coherence imaging system using an organic photorefractive material can be used as an optical tomography system for biological applications.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1793-1798
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• 2003

A series of amorphous molecules that possess both photoconductive and electro-optic properties was synthesized in order to investigate photorefractive properties of bifunctional organic-glasses. Diethylaminobenzaldehyde-diphenylhydrazone was covalently attached to 5-(4-diethylamino-benzylidene)-1,3-dimethylpyrimidine-2,4,6-trione through a flexible alkyl chain (3, 4, 5, 6 and 10 carbons) containing two ether linkages. The longer linkage not only lowered the glass transition temperature ($T_g$) of the molecules, but also allowed faster orientation of the chromophore. To examine the photorefractive properties, a 50 ${\mu}$m-thick film was prepared from the mixture of a bifunctional molecule, butyl benzyl phthalate, and $C_{60}$. The photoconductivity of this composite was as high as $8.01\;{\times}\;10^{-12}$ S/cm at 60 V/ ${\mu}$m, and the maximum diffraction efficiency ( ${\eta}_{max}$) of 50 ${\mu}$m-thick film was about 5% at 80 V/ ${\mu}$m.