Abstract: A nonlinear optical device having an optical medium and an optical element including a polarizer, an optical resonator and a reflector is provided. The optical medium includes an organic nonlinear optical material represented by a formula: ##STR1## wherein each of R.sub.1 and R.sub.2 is an alkyl group having 2 to 6 carbon atoms or a hydroxyalkyl group having 2 to 6 carbon atoms, R.sub.1 and R.sub.2 being same or different groups; or R.sub.1 is an ethyl group and R.sub.2 is an acryloyloxyethyl group (CH.sub.2 .dbd.CH--COO--CH.sub.2 CH.sub.2 --) or a methacryloyloxyethyl group (CH.sub.2 .dbd.C(CH.sub.3)--COO--CH.sub.2 CH.sub.2 --); and each of X.sub.1, X.sub.2, X.sub.3, and X.sub.4 is individually a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an alkyl ester group, or an alkylamide group, where X.sub.1, X.sub.2, X.sub.3 and X.sub.4 may be the same or different groups.

Abstract: A 2,5-disubstituted pyrazine derivative and a 2,5-disubstituted pyrimidine derivative of the formula (I): ##STR1## wherein R.sup.1 and R.sup.2 each independently represents a straight-chain or branched alkyl group containing 1 to 20 carbon atoms;X represents a halogen atom; and ##STR2## represents a pyrazine-2,5-diyl or a pyrimidine-2,5-diyl group; each useful as an electrooptical display material are disclosed. Further a liquid crystal composition comprising said compounds as well as a ferroelectric display device wherein said liquid crystal composition is used are disclosed.

Abstract: An organic nonlinear optical device having a nitrostyrene compound represented by a formula: ##STR1## wherein R.sub.1 is an ethyl group R.sub.2 is a group selected from the group consisting of an acryloyloxyethyl group (CH.sub.2 .dbd.CH--COO--CH.sub.2 CH.sub.2 --) and a methacryloyloxyethyl group (CH.sub.2 .dbd.C(CH.sub.3)--COO--CH.sub.2 CH.sub.2 --); and X.sub.1, X.sub.2, X.sub.3, and X.sub.4 are the same or different and each is selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group, an alkoxy group, an alkyl ester group, and an alkylamide group, is provided.

Abstract: A haze-free light modulating polymer dispersed liquid crystal (PDLC) material is disclosed which comprises a polymer matrix which is birefringent and possesses anisotropic optical properties similar to those of the dispersed liquid crystal microdroplets such that the PDLC material in its transparent state exhibits a refractive index that is matched for all directions of incident light providing for an optically clear, scatter-free film for all angles of view. Electrooptic light shutters are possible from this material which are transparent in the field OFF-state and opaque in the field ON-state or vice versa, depending upon the microdroplet structure and configuration of the light shutter device.

Abstract: An organic nonlinear optical material which is an optically transparent solid solution comprising (a) an organic compound component exhibiting nonlinear optical response represented by formula (I): ##STR1## wherein Z.sup.1 represents an atomic group, which together with the adjacent carbon atom, forms a substituted or unsubstituted 5- to 6-membered aromatic ring having at least one nitro group as a substituent; and Z.sup.2 represents an atomic group, which together with the adjacent nitrogen atom, forms a substituted or unsubstituted pyrrole, imidazole, pyrazole, triazole or tetrazole ring, and (b) a polymer. The nonlinear optical material exhibits high nonlinear optical response and excellent transmission to blue light.

Abstract: Optical elements having non-linear optical properties comprising a compound of the formula: ##STR1## wherein D is an electron donorA is an electron acceptor;and W, X, Y and Z are each independently H or any group capable of attachment to the pyrazolyl ring; in which the molecules of the compound are aligned so that the element has a net non-centrosymmetry, a method for their preparation, optical devices comprising such elements, and compounds of formula I.

Abstract: Optical elements having non-linear optical properties comprising a compound of the formula: ##STR1## wherein E is an electron donorA is an electron acceptor;and W, X, Y & Z are each independently H or any group capable of attachment to the pyrazolyl ring; in which the molecules of the compound are aligned so that the element has a net non-centrosymmetry, a method for their preparation, optical devices comprising such elements, and compounds of formula I.

Abstract: Methods for making a latex entrapped nematic curvilinearly aligned phases liquid crystal composition and apparatus utilizing such composition wherein the liquid crystal material is dispersed in a latex medium. Such a composition may be made by emulsifying liquid crystal material in the presence of a suspension of latex particles or, alternatively, by combining a suspension of latex particles with an emulsion of liquid crystal material.

Abstract: Optically nonlinear aromatic carboxylic acid cocrystals are provided of the formula: ##STR1## wherein each R is CN or NO.sub.2, n is 1-4, m is 1-3 and X and Y are individually (C.sub.1 -C.sub.3)alkyl, (C.sub.1 -C.sub.3)alkanolyl, (C.sub.1 -C.sub.3)alkoxycarbonyl, ar(C.sub.1 -C.sub.5)alkyl, aryl, (C.sub.1 -C.sub.3)alkoxy, hydroxy, halo or mixtures thereof.

Abstract: An optical resonant assembly which comprises a plurality of partially light-transmitting mirrors, a layer of photochromic material disposed between the mirrors, a light source providing a light beam of variable intensity incident on the layer of photochromic material and detecting means for determining transmittance values of said incident beam at different intensity levels, said photochromic material having a low quantum yield for bleaching with light of a wavelength corresponding to said light beam and being selected from pyran compounds of the general formula (I) below: ##STR1## wherein X and Y together represent a spiro-adamantylidene group or a spiro-carbocyclic or heterocyclic group or X and Y independently represent hydrogen, alkyl (preferably lower alkyl having 1 to 5 carbon atoms) or phenyl and R.sub.3 and R.sub.4 each independently represent hydrogen, alkyl, aralkyl, aryl, halogen or a heterocyclic group and R.sup.

Abstract: Optically active oxirane-2-carboxylic acid esters with a mesogenic molecular component suitable as dopants in liquid-crystal mixtures. They result in liquid-crystalline ferroelectric phases with short switching times and in electroclinic phases with large electroclinic coefficients. A further advantage lies in the fact that they induce a helix with a very small pitch so that they are also suitable for helix compensation in LC mixtures.

Abstract: The twistable liquid crystal phases contain at least two chiral compounds (admixtures), at least one exhibiting helix inversion and at least one other having a high twisting capacity. With the aid of this combination of chiral compounds possessing certain properties, it is possible to effect temperature compensation with a relatively small amount of added admixtures.

Abstract: The liquid-crystalline polymeric composition of the invention comprises (A) a non-liquid-crystalline polymeric compound and (B) a low-molecular liquid-crystalline compound each having a proton donor and/or a proton acceptor in the molecular structure and the low-molecular compound has a chiral smectic C phase. By virtue of these functional groups forming hydrogen bonds between the components, the liquid-crystalline polymeric composition of the invention is not a mere blend of the components liable to cause phase separation but is imparted with greatly increased stability and uniformity of the blend as well as responsivity of high speed.

Abstract: A wavelength converting device exhibiting high activity for SHG is disclosed, which comprises a compound represented by formula (I) ##STR1## where Ar represents the residue of a .pi.-electron conjugated molecule; and X represents a hydroxyl group, an alkoxy group, or a halogen atom.

Abstract: Arylcarboxylates of 2-hydroxypropionates are known, amongst other compounds, as dopes for converting tilted smectic liquid-crystal phases into ferroelectric liquid-crystal phases.The novel chiral aryloxypropionates of the general formula ##STR1## are two-fold chiral and in which the symbols have the following meaning: R.sup.1 denotes a straight-chain alkyl or alkoxy radical having 1 to 16 carbon atoms or a branched alkyl or alkoxy radical having 4 to 16 carbon atoms, it being possible for one or two non-adjacent CH.sub.2 groups to be replaced by a sulfur and/or oxygen atom;A denotes one, two or three aromatic or heteroaromatic rings which are linked to one another directly or via one or two COO groups;B denotes a chemical bond or one or two aromatic or heteroaromatic rings which are linked directly to one another;R.sup.2(a) if B is a chemical bond, denotes an alkyl radical having 2 to 10 carbon atoms which contains an asymmetrical carbon atom which is substituted by CH.sub.3, halogen or a COOC.sub.2 H.sub.

Abstract: A nonlinear optical element comprising 3-methyl-4-methoxy-4'-nitrostilbene useful for nonlinear optical and electro-optic effects.

Abstract: New cyclohexane derivatives of the formula IR.sup.1 --A.sup.1 --Z.sup.1 --A.sup.2 --R.sup.2 IwhereinR.sup.1 and R.sup.2 are each H, an unsubstituted or substituted alkyl group with 1-15 C atoms, it also being possible for one or two non-adjacent CH.sub.2 groups to be replaced by at least one grouping from the group comprising --O--, --CO--, --O--CO--, --CO--O--, --C.tbd.C--, --CH.dbd.CH--, --S--, --SO-- and --SO.sub.2 --, F, Cl, Br, CN or R.sup.3 --(A.sup.3).sub.p --Z.sup.2 --,A.sup.1 is --A--, --A.sup.4 --Z.sup.3 --A-- or --A--Z.sup.3 --A.sup.4 --,A is a 1,4-cyclohexylene group which is substituted in the 1- and/or 4-position by unsubstituted or substituted alkyl or fluorinated alkyl with in each case 1-5 C atoms, it also being possible for one or two non-adjacent CH.sub.2 groups to be replaced by one grouping from the group comprising --O--, --CO--, --O--CO--, --CO--O--, --C.tbd.C--, --CH.dbd.CH--, --S--, --SO-- and --SO.sub.

Abstract: This invention relates to a method for electric field orientation of liquid crystal polymers and oriented materials of liquid crystal polymers obtained by the method. This electric field orientation method comprises applying a pulsating electric field which is predominantly unidirectional and whose magnitude is varying periodically or non-periodically to a liquid crystal polymer capable of forming an optically anisotropic melt phase. The oriented material of liquid crystal polymer thus obtained has been unidirectionally oriented and polarized. This oriented, polarized material of liquid crystal polymer can be utilized as a piezoelectric material, pyroelectric material, electret material, non-linear optical element or the like.

Abstract: Non-linear optical materials contain the structural elements of the general formula I and/or I' ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.3', R.sup.4, R.sup.5, R.sup.6, R.sup.7 and Z have the meaning indicated in patent claim 1.

Abstract: A light source composed of a semiconductor laser and a nonlinear optical element which converts a laser beam emitted from the semiconductor laser to a laser beam having a shorter wavelength, disposed in the path of a laser beam produced by the laser, the nonlinear optical element containing a compound represented by formula (I): ##STR1## wherein Z.sup.1, Z.sup.2, X and n are as defined in the specification, of formula (II) ##STR2## wherein Z.sup.3 and Z.sup.4 are defined in the specification, or an acid adduct therefore. the nonlinear optical element exhibits high transmittances to blue light and generates a laser beam having a shorter wavelength than that of the laser applied.