Abstract: Ferroelectric liquid crystal compounds and compositions containing cyclohexenyl derivatives are provided. Specifically provided are compounds of formula: ##STR1## wherein R.sub.1 and R.sub.2 can be an alkyl, cycloalkyl, alkenyl, alkoxy, thioalkyl, alkylsilyl group having from one to about twenty carbon atoms. Y denotes --COO--, --OOC--, --CH.sub.2 O--, or --OCH.sub.2 --; and Ar.sub.1 and Ar.sub.2, independently of one another, can be selected from the group consisting of phenyl rings, halogenated phenyl rings and nitrogen-containing aromatic groups. In preferred embodiments the compounds of this invention contain at least one nitrogen-containing aromatic ring. Ar.sub.1 and Ar.sub.2 can be selected from 1,4-phenyl, mono- or dihalogenated 1,4-phenyl, 2,5-pyridinyl, 2,5-pyrimidyl, 2,5-pyrazinyl, 2,5-thiadiazole, 3,6-pyridazinyl and 1,4-cyclohexyl either or both be chiral racemic groups or chiral nonracemic groups.

Abstract: An arrangement (apparatus and method) for selectively modulating incident unpolarized light passing through a birefringent material, such as ferroelectric crystal. The apparatus includes a plate having one or more birefringent layers. The birefringent layer has an optic axis selectably set in a first orientation and a second orientation. A switching means controls the optical axis state of voltages to the areas of the birefringent layer. Light having passed through the birefringent layer at locations having the first orientation have a different phase from, and same polarization as, light having passed through locations with the second orientation, independent of a polarization state of the incident light. As a result, the birefringent material has a uniform state at locations where the corresponBACKGROUND OF THE INVENTIONGovernment Contract ClauseThis invention was made with Government support un contract F29601-89-C-0075 awarded by the Department of the Air Force.

Abstract: The present invention provides liquid crystals that are 3,3'-dihalogenated diphenyldiacetylenes of the general formula: ##STR1## where X and Y are, independently of one another, a halogen atom and T.sub.1 and T.sub.2, independently of one another are alkyl or alkenyl or alkoxy tail groups, R.sub.1, R.sub.2, or OR.sub.3, respectively, wherein R.sub.1 and R.sub.3, independently of one another, are straight-chain or branched alkyl groups having three to twenty carbon atoms and R.sub.2 is a mono or diene which may be branched or straight-chain having three to twenty carbon atoms. R.sub.1, R.sub.2, or R.sub.3 may be substituted with one or more halogens, particularly fluorines, except that the C-1 carbon of an OR.sub.3 tail may not be halogenated. One or two non-neighboring CH.sub.2 groups of R.sub.1 or R.sub.3 may be substituted with an O atom, except that the C-1 CH.sub.2 group of an OR.sub.3 tail may not be substituted with an O atom. Liquid crystals in which X=Y=fluorine and T.sub.1 =T.sub.

Abstract: The subject application discloses a chiral nonracemic composition of the general formula:R.sub.1 --Ar--O--CH.sub.2 --C*HX--C*HY--CH.sub.2 --O--R.sub.2wherein R.sub.1 is an achiral tail of two to sixteen carbons; Ar is an achiral FLC core of at least two rings; * denotes a chiral carbon; X and Y are halogens; and R.sub.2 is one to ten carbon atoms. The --O--CH.sub.2 --C*HX--C*HY--CH.sub.2 --O-- segment comprises the chiral proximal segment of the chiral tail; the proximal segment is selected from the enantiomers 2R,3R-dihalo and 2S,3S-dihalo. R.sub.2 is the distal segment of the chiral tail.

Abstract: Chiral nonracemic molecules which are useful in the preparation of high polarization density FLC compositions and which have the following structure are provided: ##STR1## wherein Ph is a 1,4 substituted phenyl group, m=2 and n=1 or m=1 and n=2, asymmetric carbons are indicated by *. R is an alkyl group having three to fifteen carbon atoms, and R' is an alkyl group having one to seven carbons. The invention in particular provides compounds having the R,R or S,S configuration in the epoxide tail. The epoxy phenylbenzoates of this invention display a property of inducing a tilt angle greater than expected in FLC compositions in which they are combined.

Abstract: Chiral, nonracemic compounds of the general formula: ##STR1## wherein m and n are either both zero, both equal one or n is equal to one and m is equal to zero, X and Y and Z are halogens, R' is an alkyl or alkoxy group having three to fifteen carbons, R is an alkyl group having one to fifteen carbons, and Ar is a 4,4'-substituted phenylvenzoate, 4,4'-substituted biphenylbenzoate, 5,4-substituted 2-phenylpyrimidine or 4,4'-substituted biphenyl core, and wherein * indicates a chiral center, which are useful as ferroelectric liquid crystal components having high polarization are described.