Deutschetelekom Ag

Tetragon Lc Chemie Ag

Haase, Wolfgang, Prof. Dr.

Wolfgang Haase

Wolfgang Dultz

Leonid Beresnev

Leonid Alexseevich Beresnev

Arkadii Onokhov

Lev M Blinov

Elena Anatolievna Konshina

Galina Patrusheva

Thomas Weyrauch

Artsiom Lapanik

Sergei Pikin

Ashok Bizadar

Dirk Ganzke

Yuri Galyametdinov

Eduardo Soto Bustamante

Eugene Pozhidaev

Sergei Yablonsky

Lapanik Artsiom

Chiral liquid crystal compounds of the general formula (1): 

Chiral compounds, cholesteric and ferroelectric liquid crystal compositions comprising these chiral compounds, and liquid crystal displays comprising these liquid crystal compositions

An electrically drivable light modulator having liquid crystal layers, which are disposed one behind the other and are enclosed between transparent plates having a surface anisotropy that orients the molecules of the liquid crystals and having electrodes for generating an electric field in the liquid crystals, at least two layers of helical, smectic, ferroelectric liquid crystals are situated one behind the other in the path of rays of a light beam to be modulated. The directions of the fast and slow axes of the individual layers are rotated relatively to each other so that the polarization of the light beam is the same upstream and downstream from the modulator. An adaptive, optical device has a field of light modulators configured in a raster-type array, in which the modulators are situated in the path of rays of the device, each individual light modulator being able to be driven to compensate for unsharpness occurring on a point-by-point basis in an image to be processed.

Electro-optical light modulator

In order to substantially reduce temperature-dependent influences and attendant long switching times in the case of an optical liquid crystal modulator having at least one ferroelectric liquid crystal and in a method for operating an optical liquid crystal modulator, the ferroelectric liquid crystals are provided to have a DHF mode and to exhibit an operating range of an electric field of more than 20 V/&#x3bc;m at the location of the liquid crystal.

Device and method for the temperature-independent operation of electro-optical switches on the basis of ferroelectric liquid crystals having a deformed helix

A liquid crystalline material having a lamellar structure can be used for phase modulation. A liquid crystal having arcuated or angular dimer molecules so that the molecules each include two central units, and the longitudinal axes of the two central units exhibit at least approximately oppositely directed inclination angles with respect to the layer normal z. By configuring the two central units of the dimer molecule in accordance with the present invention, the molecular index ellipsoid, which is essentially composed of the components of the two readily polarizable central units, may be positioned such that the optical axis is always situated in parallel to the layer normal z, making it possible to prevent the light, which propagates in a defined direction orthogonally to the layer normal through the liquid crystalline material, from undergoing a polarization modulation simultaneously with the phase modulation.

Liquid crystalline materials for optical phase modulation

A method for applying a light-blocking layer between a photoconducting layer and a mirror when making an optically addressable spatial light modulator (OASLM) using a chemical vapor deposition process. The light-blocking layer and the photoconducting layer are applied in a shared process step in which both the thickness and composition of the photoconducting layer to be applied to the transparent electrode, as well as the thickness and composition of the light-blocking layer to be applied to the photoconducting layer are determined by a time-related change of the variation of the gas composition during the deposition process. The structure of the OASLM can be optimally adapted to a desired purpose.

Process for applying a light-blocking layer between a photoconducting layer and a mirror when manufacturing an optically addressable spatial light modulator

In an arrangement and a method for electrically controlling the intensity of non-polarized light, a polarizing beam splitter is acted upon by the light to be controlled via an input face such that the light is split into two polarized light bundles that are orthogonal with respect to each other. Provision is made that a first reflecting device is configured for the reflection of at least one of the polarized light bundles, so that both polarized light bundles run in parallel. At least one electro-optical element is provided in a path of the parallel running polarized light bundles. The polarization is changed as a function of the supplied control voltage. Also provided is a second reflecting device for reflecting the light bundles in the opposite direction. The light bundles pass through the at least one electro-optical element twice and are directed by the first reflecting device to the polarizing beam splitter, and the controlled light can be extracted from at least one output face of the polarizing beam splitter.

Arrangement and method for electrically controlling the intensity of unpolarized light

An electro-optic material that is characterized by short reaction times when working with a low drive voltage. For that, the electro-optic material has a lamellar liquid crystal (,), which contains one or more components and into which chiral molecules (,), whose longitudinal axes (m) are longer than the longitudinal axes of the molecules (,) forming the lamellar liquid crystal, are introduced at a predefined concentration, so that the longitudinal axes (m) of the chiral molecules (,) are tilted, without an external electric field, statistically by a predefined angle (&thgr;,) toward the normal (z) of the layer of the lamellar liquid crystal (,).

Electro-optical material having a lamellar liquid crystal structure

A device featuring liquid crystals for local reduction of the intensity of incident light is described. This device protects the eyes or the video camera against blinding, or the light-sensitive medium against local damage by automatically reducing the intensity of the incident light emitted by brightly illuminated objects, while the brightness of poorly illuminated objects is not suppressed. The device uses optically addressed spatial light modulators (OASLM) on the basis of a semitransparent photoconducting film in contact with ferroelectric liquid crystals (FLC). The DHF effect (deformation of the helix structure) in ferroelectric liquid crystals (FLC) with helix-shaped structure is used here. The drive voltage has a frequency of 10.sup.2 to 10.sup.3 Hz at an amplitude of .+-.20 V, which is 10-50 times higher than that of devices operating with nematic liquid crystals. The device allows moving objects to be observed against the background of a bright light source (sun, lamp, etc.). A switchable shutter on the basis of ferroelectric liquid crystals (FLC) is used at a molecular inclination of .theta..sub.o .noteq.45.degree.. To increase the average transmission of the device, a second FLC layer with chiral smectic A or C phase with a switchable molecular inclination of .theta..sub.c =45.degree.-.theta..sub.o or .theta..sub.c =.theta..sub.o is used.

Ferroelectric liquid crystal device for local reduction of light

A method of preparing a pyroelectric mixture, especially for pyroelectric and piezoelectric components. At least two compounds are mixed in a prescribed ratio. One compound contains polymerizable and preferably achiral liquid-crystal monomers and the other a preferably achiral liquid-crystal polymer or copolymer. Each compound also contains hydrogen-bridging substituents. The mixture is heated to above its specific vitrification point. An electric field is applied to polymerize the monomer and polarize the mixture. The mixture is cooled to below its specific glass transition point with the field still present.

Growing community of inventors

Reinheim, Germany

Wolfgang Haase