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Tunable properties of light propagation in photonic liquid crystal fibers

Szaniawska K., Nasilowski T., Woliński T. R., Thienpont H.

Opto-Electronics Review

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2006

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Vol. 14, No. 4

339-343

EN

Tunable properties of light propagation in photonic crystal fibers filled with liquid crystals, called photonic liquid crystal fibers (PLCFs) are presented. The propagation properties of PLCFs strongly depend on contrast between refractive indices of the solid core (pure silica glass) and liquid crystals (LCs) filing the holes of the fiber. Due to relatively strong thermo-optical effect, we can change the refractive index of the LC by changing its temperature. Numerical analysis of light propagation in PLCF, based on two simulation methods, such as finite difference (FD) and multipole method (MM) is presented. The numerical results obtained are in good agreement with our earlier experimental results presented elsewhere [1].

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Propagation properties of photonic crystal fibers filled with nematic liquid crystals

Woliński T. R., Szaniawska K., Bondarczuk K., Lesiak P., Domański A. W., Dąbrowski R., Nowinowski-Kruszelnicki E., Wójcik J.

Opto-Electronics Review

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2005

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Vol. 13, No. 2

177-182

EN

The paper presents the latest experimental results on propagation properties of a photonic crystal fiber infilled with a nematic liquid crystal characterized by either extremely low (of the order of ~0.05) or relatively high (of the order of ~0.3) material birefringence. The nematic liquid crystal was introduced into the micro holes of the photonic crystal fiber by the capillary effect. Due to anisotropic properties of the obtained photonic liquid-crystal fiber, guiding mechanism that has to be attributed to the photonic band gap effect has been demonstrated.

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Polarization mode dispersion in birefringent microstructured fibers

Woliński T. R., Lesiak P., Szaniawska K., Domański A. W., Wójcik J.

Optica Applicata

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2004

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Vol. 34, nr 4

541-549

EN

The possibility of compensation of polarization mode dispersion (PMD) by using highly birefringent (HB) fibers was proposed a few years ago. In this paper, we present our results of measurement of PMD value in a new type of birefringent microstructured fibers: photonic crystal fibers (PCF). Their low temperature sensitivity and simultaneously high longitudinal strain sensitivity make them possible to be used as PMD compensation components.

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Gel–glass transition in silica and nitrided silica aerogels – experiment and computer modelling

Szaniawska K., Murawski L., Rybicki J., Witkowska A., Walewski M.

Optica Applicata

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2003

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Vol. 33, nr 1

75-81

EN

Nitrided silica aerogel was sintered at 1600 °C in vacuum or nitrogen atmosphere and the effect of densification was compared with that observed in silica aerogel. It has been shown that homogeneous oxynitride glasses containing 8.4–13 wt% can be obtained by densification of nitrided aerogels. The densification process of nitrided aerogels was simulated by computer modeling using classical molecular dynamics (MD) simulations. MD simulations have shown that densification process proceeds in a similar way as in the experiment. In addition, the simulations indicate that oxynitride glasses can be obtained by densification of Si–O–N system.

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Oxynitride glasses prepared by densification of nitrided silica aerogels.

Szaniawska K., Murawski L., Pastuszak R., Walewski M.

Optica Applicata

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2000

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Vol. 30, nr 4

529-536

EN

Silica aerogels were nitrided by ammonia treatment at temperatures ranging from 700 degrees C to 1300 degrees C. It was found that the amount of nitrogen incorporated in silica aerogel depends on the final temperature of ammonolysis and on the time of heat treatment. The specific surface area of nitrided aerogels remains large and decreases with the temperature of ammonolysis and with nitrogen content. Nitrided aerogels can be converted into dense homogeneous oxynitride glasses containing 8.4-13.0 wt% of nitrogen by heat treatment at 1600 degrees C in vacuum or in nitrogen atmosphere. The spectra of the Fourier transform infrared spectroscopy (FTIR) reveal that Si-N bonds exist in nitrided aerogels as well as in oxynitride glasses.