279 research outputs found

    Nonlocal communication with photoinduced structures at the surface of a polymer film

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    Nonlocal communication between two laser light beams is experimented in a photochromic polymer thin films. Information exchange between the beams is mediated by the self-induction of a surface relief pattern. The exchanged information is related to the pitch and orientation of the grating. Both are determined by the incident beam. The process can be applied to experiment on a new kind of logic gates.Comment: 7 pages, 4 figures, 2 table

    Surface relief grating formation on nano-objects

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    We exploit the photoinduced migration effect in azopolymer thin films to induce surface relief patterning of nano-objects. Manipulation and precise control of the molecular order is achieved at the nanoscale. Interaction between a laser beam from an argon laser and the azopolymer nano-objects induces structures on the surface. The self-patterning process is observed to depend on the laser beam polarization

    Cooperative interaction in azopolymers upon irradiation

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    We present two optical experiments which permits to evaluate individual and collective behaviours of molecules leading to a well-organized pattern in a randomly activated molecular assembly; in a first experiment a white light and a laser beam are sent together; in a second experiment a low-power coherent beam carr 3rd International Symposium on Molecular Materials (MOLMAT

    Second harmonic generation and photochromic grating in polyurethane films containing diazo isoxazole chromophore

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    The chromophoric intermediate: 2,2′-({4-[(E)-(5-methylisoxazol-3-yl)diazenyl]phenyl}-imino)diethanol was used in polyaddition reaction with di-isocyanate to obtain a new polyurethane polymeric material showing nonlinear optical and photochromic properties. The maximum absorption band of the polymer film was at 418 nm. The illumination of the film with crossed beams of the 488 nm Ar+ laser yielded surface relief grating of regular structure. Measurement of the frequency doubling signal with 1064 nm laser indicated the polymer as interesting material for photooptical applications. The measured nonlinear optical coefficient, d33, reached 90.2 pm/V

    Second harmonic generation and photochromic grating in guest-host polymer system containing azo amide chromophores

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    The azo sulfonamide chromophores containing long aliphatic chain were used as active nonlinear optical (NLO) materials in films prepared by spin-coating on glass surfaces. The sulfonamides were: N-{4-[{4-[(pyrimidin-2-ylamino)sulfonyl]phenyl} diazenyl] phenyl} decanamide (Amid P); N-{4-[{4-[(1,3-thiazol-2-ylamino)-sulfonyl]phenyl} diazenyl] phenyl} decanamide (Amid T) and N-{4-[(4-nitrophenyl)-diazenyl]-phenyl}undec-10-enamide (Amid N). The host matrix was a copolymer of methyl and butyl methacrylate. The formation of diffraction grating by the guest-host system was successful only in the case of Amid N. The pitch and amplitude of the grating was 930 nm and ca. 45 nm, respectively. Quantum chemical calculations revealed that the chromophores were moderate NLO-fores showing static beta values of ca. 110-130 m(4)/V. Two procedures were involved to align chromophores to determine first order NLO susceptibility: a) corona poling, and b) all-optical poling. The NLO coefficient d(33) determined in corona poled film was 25.2, 28.6 and 93.2 pm/V for Amid P, T and N, respectively
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