摘要:

A series of α,ω-bis[(3-formyl)carbazolyl]alkane monomers have been prepared and copolymerized with bis(cyanoacetate) to provide novel accordion-type carbazole main-chain polymers. These main-chain polymers are soluble in common organic solvents, and have glass transition temperatures in the range of 94-117°C and molecular weight 25000-72000.

ISSN:1058-725X    

DOI:10.1080/10587259508033974

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The nonlinear optical anisotropy of ply(p-phenylene benzo-bisthiazole) (PBT) Langmuir-Blodgett (LB) films has been investigated by optical third-harmonic generation measurement. Polymer backbones of PBT in LB films were aligned along the dipping direction. The χ(3)xxxx, χ(3)yyyyand χ(3)xxyyvalues were determined by rotational Maker fringe method to be 11.3 × 10−12esu., 1.5 × 10−12esu. and 0.9 × 10−12esu, respectively. These nonlinear optical anisotropies can be explained well by assuming a Gaussian orientational distribution of one-dimensional π-conjugated chains.

ISSN:1058-725X    

DOI:10.1080/10587259508033975

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Third-order electric susceptibility x(3)of tin-phthalocyanine film deposited on a boro-silicated glass plate coated with rubbing-treated polyimide thin film was measured by a method of THG Maker-fringe technique. In the resonant absorption spectral range, the maximum values of x(3)of aggregated tin-phthalocyanine were 220×10−12esu obtained in the direction perpendicular to the rubbing direction, but the values parallel to the rubbing were 47×10−12esu. The large anisotropy of x(3)was induced by a preferred orientation of tin-phthalocyanine microcrystals when anisotropic substrates were heated at 200°C.

ISSN:1058-725X    

DOI:10.1080/10587259508033976

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The second-order nonlinear optical coefficients d33(-2ω:ω, ω) of polymer films doped with novel azo dyes, which have a perfluoroalkylsulfonyl group as an electron acceptor and an extended π-electron conjugated system, are determined by second-harmonic generation (SHG) measurements. Thin polycarbonate (PC) film doped with 4-(4-(4-perfluorobutylsulfonylphenylazo) naphthylazo)-N-ethyl-N-hydroxyethylaniline showed a large d33value, 67 pm/V, at a wavelength of 1064 nm. The decay of the d33values was slow due to the stability of the molecular arrangement in a polymer matrix at high temperature. In addition, a side-chain nonlinear optical polymer with this novel disazo dye is synthesized and the decay of d33values is estimated.

ISSN:1058-725X    

DOI:10.1080/10587259508033977

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The second-order hyperpolarizabilities (β) of two categories of organic ionic species were evaluated by the hyper Rayleigh scattering method. The ⟨β⟩ of (dimethylamino)stilbazolium analogues in methanol with long cut-off wavelength more than 600 nm, which can be used for electro-optic modulation, were evaluated to be in the order of 10−27esu using 1064 nm light as a fundamental beam. Aromatic sulfonates in the second category were found to have comparatively large |β| values irrespective of short cut-off wavelength: In the case of sodiump-toluenesulfonate with cut-off of 280 nm, |β| in methanol was 2.2×10−29esu and was about two thirds ofp-nitroaniline with cut-off of 445 nm.

ISSN:1058-725X    

DOI:10.1080/10587259508033978

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Microcrystals of two different types of diacetylene monomers,i.e.4BCMU known for giving a soluble polydiacetylene and 14-8 ADA known as an amphiphilic diacetylene, were prepared and in their solid-state polymerization behaviors were investigated. The polymerization of 4BCMU proceeded quantitatively in the perfect crystalline lattice to give blue-colored polymer crystals. Averaged molecular weight of poly-4BCMU was found to be. proportional to microcrystal size, implying that the solid-state polymerization proceeds from one end to the other end of microcrystals. 14-8 ADA microcrystals gave very stable water dispersion even after polymerization, so that the detailed analysis of polymerization behaviors was possible. Size-dependent spectral change and final conversion found for 14-8 ADA were discussed in terms of strain and thermal motion of the crystal lattice.

ISSN:1058-725X    

DOI:10.1080/10587259508033979

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We have demonstrated technique for measuring the third-order nonlinear optical susceptibility χ(3)(-3ω, ω, ω, ω) based on internal reflection. Using this technique, we observed third-harmonic generation from a poly-DCH film deposited on oriented LB film of poly(3BCMU). Its χ(3)was 2.1 times as large as an another film with no LB film. This suggests that the oriented LB film contributes to the alignment of the DCH monomer deposited on it.

ISSN:1058-725X    

DOI:10.1080/10587259508033980

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Phase-matching properties of a P1 symmetry crystal, (-)-1-1-(4-dimethylaminophenyl)-2-(2-hydropropylamino) cyclobutene-3, 4-dione, are theoretically and experimentally investigated. The nonlinear-optical coefficients dijare calculated by the oriented-gas model and the effective coefficients are estimated to be 243 pm/V and 23 pm/V at a fundamental wavelength of 1064 nm for the type I and the type II phase-matching of the second-harmonic generation, respectively. The experimental results of the type II second-harmonic generation using the largest plane of the as-grown crystal are given.

ISSN:1058-725X    

DOI:10.1080/10587259508033981

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Alloying of metals forming linear chains in the one-dimensional metal complexes was performed by use of vacuum evaporation technique. Mixture of two different metal complexes with dimethylglyoxime could be fabricated into a thin film with optical quality. They showed a strongd-ptransition band in the visible region, and their peak wavelengths subsequently varied in proportion to the mixing ratio of metal complexes. Their third-order nonlinear optical property was also investigated by third-harmonic generation measurements.

ISSN:1058-725X    

DOI:10.1080/10587259508033982

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Transparent films of one-dimensional tetranuclear platinum complex, which has some mixed-valence states, was successfully prepared. Alumina gel and poly vinyl alcohol (PVA) were tested their suitabilities for a matrix. In the alumina matrix, their absorption spectra show that the Ptcomplex exists as the mixture with various valence states. On the contrast, in the PVA matrix, the absorption spectrum of the complex is unchanged from its solute sample state. THG properties were also investigated for their thin films.

ISSN:1058-725X    

DOI:10.1080/10587259508033983

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor