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1

Comparison of Different Liquid Crystal Materials under Planar and Homeotropic Boundary Conditions in Capillaries

100%

Chychłowski M., Ertman S., Nowinowski-Kruszelnicki E., Dąbrowski R., Woliński T.

Acta Physica Polonica A

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2011

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vol. 120

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issue 4

582-584

EN

We present a thermally-induced liquid crystal orientation method by applying an extra orienting layer onto an inner capillary surface that can induce either planar or homeotropic liquid crystal boundary conditions. Experimental evidence of boundary-induced orientation in two types of liquid crystal (nematic, chiral nematic) in a capillary are shown.

2

Photo-Induced Orientation of Nematic Liquid Crystals in Microcapillaries

86%

Chychłowski M., Ertman S., Tefelska M., Woliński T., Nowinowski-Kruszelnicki E., Yaroshchuk O.

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issue 6

1100-1103

EN

Axial and transversal orientational configurations of a nematic liquid crystal 6CHBT are realized inside glassy cylindrical capillaries by using photoalignment technique. It is demonstrated that this principle can be effectively used to enforce liquid crystal alignment in the desirable direction. It can be applied to control liquid crystal alignment in the photonic crystal fibers showing great potential for the modern telecommunication technologies.

3

Numerical Simulations of Electrically Induced Birefringence in Photonic Liquid Crystal Fibers

86%

Ertman S., Woliński T., Beeckman J., Neyts K., Vanbrabant P., James R., Fernández F.

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issue 6

1113-1117

EN

It has been recently experimentally demonstrated that propagation and polarization properties of the photonic liquid crystal fibers can be effectively tuned with the electric field. In particular, effective electric tuning of the phase birefringence has been obtained in the photonic liquid crystal fibers based on the high index glasses. Accurate numerical simulations of the impact of electric field on the guiding properties of the photonic liquid crystal fibers require complex methods, in which all important physical properties of the liquid crystal are taken into account (optical anisotropy, molecular orientation and relatively high losses). In this paper we present two different numerical approaches based on the finite element method. First one utilizes the simplified assumption of the "collective tilt" of molecules, and gives rough estimation of the phase birefringence tuning range. The second approach is much more rigorous, since electrically induced reorientation of the liquid crystal is calculated with a Q-tensor method giving the values of the inhomogeneous permittivity tensor. The value of the electrically induced birefringence calculated with the second method is in a good agreement with the experimental results.

4

Photonic Liquid Crystal Fibers with Polymers

59%

Woliński T., Tefelska M., Mileńko K., Siarkowska A., Budaszewski D., Domański A., Ertman S., Orzechowski K., Rutkowska K., Sierakowski M., Nowinowski-Kruszelnicki E., Dąbrowski R., Mergo P.

Acta Physica Polonica A

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2013

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vol. 124

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issue 3

613-616

EN

Photonic liquid crystal fibers with polymers constitute a new solution based on liquid crystals and microstructured polymer optical fibers opening up new areas in innovative sensing and photonic devices applications. Compared with their silica-based microstructured fibers, it is easier to fabricate exotic microstructured polymer optical fibers by extrusion or drilling at low temperature; their nonlinearity is potentially stronger, the range of available polymers that may be drawn is more diverse and the biocompatibility of polymers is often better. Liquid crystals due to their attractive properties i.e., the high birefringence, high electro-optic and thermo-optic effects are a very good candidate for microstructured polymer optical fiber infiltration to obtain tunable all-in-fiber innovative photonic devices. The paper will discuss basic properties and possible applications of the polymer photonic liquid crystal fibers that will arise from their high optical tunability with external and internal factors. Current research effort is directed towards two main solutions: photonic crystal fibers and microstructured polymer optical fiber-based structures, both infiltrated with liquid crystals of tailored optical properties.

5

Comparison of Bragg and Polarimetric Optical Fiber Sensors for Stress Monitoring in Composite Materials

59%

Domanski A., Lesiak P., Milenko K., Budaszewski D., Chychlowski M., Ertman S., Tefelska M., Wolinski T., Jedrzejewski K., Lewandowski L., Jasiewicz W., Helsztynski J., Boczkowska A.

Acta Physica Polonica A

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2009

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vol. 116

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issue 3

294-297

EN

Composite structures are made of two or more components with significantly different physical or chemical properties and they remain separate and distinct in a macroscopic level within the finished structure. This feature allows for introducing optical fiber sensors into the composite material. These sensors can demonstrate stress distribution inside tested material influenced by external tensions. Two types of the optical fiber sensors are used as the 3D structure. One of them is based on application of fiber Bragg grating inside the core of the fiber. Longitudinal stress changes parameters of the Bragg grating and simultaneously, spectral characteristics of the light transmitted through the fiber. The second one is based on application of highly birefringent fibers which, under external stress, introduce polarization changes of the output light.

Refine search results

Comparison of Different Liquid Crystal Materials under Planar and Homeotropic Boundary Conditions in Capillaries

Photo-Induced Orientation of Nematic Liquid Crystals in Microcapillaries

Numerical Simulations of Electrically Induced Birefringence in Photonic Liquid Crystal Fibers

Photonic Liquid Crystal Fibers with Polymers

Comparison of Bragg and Polarimetric Optical Fiber Sensors for Stress Monitoring in Composite Materials