ISSN:1058-725X    

DOI:10.1080/10587259208028739

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

An overview is presented on photo-induced phase transitions in quasi-one-dimensional molecular systems. The phenomena are characterized by evolution of the local molecular domains induced by photo-excitations into the new macroscopic phase via collective interaction of domain wall excitations.

ISSN:1058-725X    

DOI:10.1080/10587259208028740

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The design of macromolecules described as “hairy rods” proved to be most successful in the attempt to construct layered structures of optimized quality by the Langmuir—Blodgett—technique. Novel types of supramolecular architectures could be realized best described as “molecularly reinforced liquids”. First attempts to build prototype devices based on layered assemblies of these non—conventional polymers are reported. The relative orientation of the rod—like macromolecules can be changed deliberately in each layer as well as the chemical nature of the polymer such that true nanocomposites are obtained.

ISSN:1058-725X    

DOI:10.1080/10587259208028741

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:1058-725X    

DOI:10.1080/10587259208028742

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We study the lasing behavior and photo induced quenching of dye doped polystyrene microspheres with diameter ranging from 10 μ to 92μ. Lasing of the spherical cavity modes is clearly observed. Emission from individual sphere placed on a glass plate is examined under the pumping of nanosecond pulses which are tuned to the absorption band of the dye. Intensity of each lasing line is strictly controlled by additional irradiation of monochromatic laser which can couple to resonance modes of the cavity. The line intensity plummets down when the additional beam frequency matches to the resonances of the modes which have the same radial profile of relevant mode.

ISSN:1058-725X    

DOI:10.1080/10587259208028743

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Organic nonlinear optical materials have developed to the point where applications in practical devices may now be contemplated. For second order nonlinear systems, these applications fall into two classes: frequency doubling and electro-optic switching and modulation. Chromophores already exist with values of the second order molecular hyperpolarizability β large enough for electro-optic applications. The situation for frequency doubling is not nearly as promising. The absorption maximum of the chromophore and the magnitude of β cannot be independently optimized within a given class of chromophores (e.g. benzenes, stilbenes, tolanes). Large values of β seem to be correlated with absorption maxima that are shifted to long wavelengths. This means that those chromophores that are the most efficient for frequency doubling will also be the most likely to absorb photons generated at the second harmonic wavelength. This relationship can be easily understood, at least in principle, by referring to a simple Hückel model of a prototypical nonlinear chromophore.

ISSN:1058-725X    

DOI:10.1080/10587259208028744

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

We have developed means for processing conjugated polymers to allow fabrication of a variety of semiconductor device structures. These polymers include polyacetylene prepared via the Durham precursor route and various poly(arylene vinylenes) prepared via sulphonium precursor polymers. We have shown that these devices exhibit novel electro-optical properties which depend for their operation on the non-linear character of the electronic excitations of the polymer chain. We discuss here the use of poly(phenylene vinylene) and derivatives as the active layers in light-emitting diodes.

ISSN:1058-725X    

DOI:10.1080/10587259208028745

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

ISSN:1058-725X    

DOI:10.1080/10587259208028746

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

With Bacteriorhodopsin (BR) it will be demonstrated that biological systems - optimized by nature under evolutionary conditions - can be applied with great success to solve material requirements in technical systems. The possibility of genetic engineering further increases the technical applicability of these systems. The application of BR and its variants as a molecular processing unit in optical data processing will be shown in several examples.

ISSN:1058-725X    

DOI:10.1080/10587259208028747

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Quantum chemical investigations of the electronic structure of the design carbazole (Cz) containing supermolecules, supramolecules, single charge donor and acceptor molecules were performed in the framework of the semiempirical neglect of differential overlap (MNDO) method. The data obtained show that it is a small charge redistribution in Cz-(CH2)4-1,2,4,5-tetracyanobenzene (TCNB) and Cz::TCNB. These designed derivatives are potential molecular photo-diodes. The sequence of the stability of the Cz containing supramolecules is found. The modeling of the photoinduced charge separation in Cz, TCNB, 2,4,7-trinitro-9-diciano-fluorene (TN9(CN)2F) and 2,4,5,7-tetranitro-9-diciano-fluorene (TeN9(CN)2F) molecules was done.

ISSN:1058-725X    

DOI:10.1080/10587259208028748

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor