Abstract: The present invention relates to a tuneable optical microcavity, characterised in that it comprises electrodes (12) on substrates (11), wherein the electrodes are comprised in the structure of dielectric or metal mirrors (13), or each of the electrodes has at least one dielectric or metal minor (13) on it, or the electrodes are semitransparent metal minors (13), wherein the mirrors are preferably located at a separation being a multiple of ½ lambda, where lambda is the central wavelength of the cavity mode, the cavity between the mirrors being filled with material (15) that changes the effective refractive index under the influence of external fields, preferably such as electric, magnetic field, thermal and mechanical stress.

Abstract: A smectic A composition with the positive dielectric anisotropy exhibiting a monolayer smectic A structure (SmA1), which shows a phase transition from a smectic A phase to an isotropic phase (SmA-Iso) or a phase transition from a smectic A phase through a nematic phase to an isotropic phase (SmA-N-Iso) and includes at least two fluorinated compounds selected from the families of fluorinated derivatives of biphenyls and terphenyls expressed by the general formulae 1-12. For ensuring of the high level of the conductivity the composition is doped with the ionic amidynium salts and/or the ionic potassium complexes of the crown ethers wherein the charge on the cation is delocalized. Such a structure of the ionic compound ensures the better solubility in the liquid crystalline fluorinated composition in comparison to that observed for quaternary ammonium salts.

Abstract: The racemic and chiral compounds expressed by common formula 1 and formula 2: wherein the lateral substituents X1, X2, X3, X4, X5, X6, X7 and X8 in the benzene rings represent independently hydrogen and fluorine atoms, bridge group Z represent independently the single bond or COO, CH2CH2, CH2O and OCH2 group, substituent Y represents CH3, or CH2F, CHF2, CF3, C2H5 group, symbols n, m, r and t are independently integers of 1 to 8; symbols p and s signify independently number of 0 to 1 and its orthoconic antiferroelectric long helical pitch mixtures prepared by the methods 1) to the racemic components selected from compounds 1 are added chiral components selected from the compound of formula 1 and/or chiral components selected from the compounds of formula 2 and/or another optically active compounds with high helical twisting power, 2) to chiral compound 1 which helical pitches increases with the temperature increase is added chiral compound 1 which helical pitch decreases with temperature increase.

Abstract: The racemic and chiral compounds expressed by common formula 1 and formula 2: wherein the lateral substituents X1, X2, X3, X4, X5, X6, X7 and X8 in the benzene rings represent independently hydrogen and fluorine atoms, bridge group Z represent independently the single bond or COO, CH2CH2, CH2O and OCH2 group, substituent Y represents CH3, or CH2F, CHF2, CF3, C2H5 group, symbols n, m, r and t are independently integers of 1 to 8; symbols p and s signify independently number of 0 to 1 and its orthoconic antiferroelectric long helical pitch mixtures prepared by the methods 1) to the racemic components selected from compounds 1 are added chiral components selected from the compound of formula 1 and/or chiral components selected from the compounds of formula 2 and/or another optically active compounds with high helical twisting power, 2) to chiral compound 1 which helical pitches increases with the temperature increase is added chiral compound 1 which helical pitch decreases with temperature increase.