The present invention provides a liquid crystal display device, which comprises: cholesteric liquid crystals and polymer fragments. By adding polymer fragments, the upper and lower substrates of the liquid crystal display device of the present invention may control the alignment of the liquid crystals and have excellent electro-optical characteristics without the use of an alignment film; furthermore, the polymer fragments are modified with a vertical alignment agent, DMOAP to form a radial structure so as to improve the contrast. The present invention also provides a method for preparing a liquid crystal display device in a simple way, so that the liquid crystal display device has the electro-optical characteristics of high contrast, low threshold voltage, and fast response time.

The present invention relates to liquid-crystalline media (LC media) having negative or positive dielectric anisotropy comprising self-aligning mesogens (SAMs) which effect homeotropic (vertical) alignment of the LC media at a surface or the cell walls of a liquid-crystal display (LC display). The invention therefore also encompasses LC displays having homeotropic alignment of the liquid-crystalline medium (LC medium) without conventional imide alignment layers. The LC media may be supplemented by a polymerizable or polymerized component, which serves for stabilization of the alignment, for adjustment of the tilt angle and/or as passivation layer.

The present invention relates to liquid-crystalline media (LC media) having negative or positive dielectric anisotropy comprising self-aligning mesogens (SAMs) which effect homeotropic (vertical) alignment of the LC media at a surface or the cell walls of a liquid-crystal display (LC display). The invention therefore also encompasses LC displays having homeotropic alignment of the liquid-crystalline medium (LC medium) without conventional imide alignment layers. The LC media may be supplemented by a polymerizable or polymerized component, which serves for stabilization of the alignment, for adjustment of the tilt angle and/or as passivation layer.

An optical device includes one or more volume phase holographic gratings each of which includes a photosensitive layer whose optical properties are spatially modulated. The spatial modulation of optical properties are recorded in the photosensitive layer by generating an optical interference pattern using a beam of light and one or more liquid crystal master gratings. The volume phase holograms may be configured to redirect light of visible or infrared wavelengths propagating in free space or through a waveguide. Advantageously, fabricating the volume phase holographic gratings using liquid crystal master grating allows independent control of the optical function and the selectivity of the volume phase holographic grating during the fabrication process.

An optical device includes one or more volume phase holographic gratings each of which includes a photosensitive layer whose optical properties are spatially modulated. The spatial modulation of optical properties are recorded in the photosensitive layer by generating an optical interference pattern using a beam of light and one or more liquid crystal master gratings. The volume phase holograms may be configured to redirect light of visible or infrared wavelengths propagating in free space or through a waveguide. Advantageously, fabricating the volume phase holographic gratings using liquid crystal master grating allows independent control of the optical function and the selectivity of the volume phase holographic grating during the fabrication process.

The invention relates to a reflecting cell including at least two substrates covered by an electrode and facing each other, the substrates delimiting between them a volume which separates them and which is filled with a cholesteric liquid crystal-type material, both electrodes being intended to be connected to a voltage source. This cell includes at least one half-wave plate arranged between both substrates and dividing the volume into two compartments, each enclosing a part of a same cholesteric liquid crystal.

The invention relates to a reflecting cell including at least two substrates covered by an electrode and facing each other, the substrates delimiting between them a volume which separates them and which is filled with a cholesteric liquid crystal-type material, both electrodes being intended to be connected to a voltage source. This cell includes at least one half-wave plate arranged between both substrates and dividing the volume into two compartments, each enclosing a part of a same cholesteric liquid crystal.

A polysiloxane elastomer containing liquid crystal lateral chain, and a smart watch made therefrom are disclosed. The polysiloxane elastomer containing liquid crystal lateral chain includes a polysiloxane backbone chain and a lateral chain formed by a liquid crystalline monomer and connected with the polysiloxane backbone chain, wherein the polysiloxane backbone chain is crosslinked by a crosslinking agent.

A polysiloxane elastomer containing liquid crystal lateral chain, and a smart watch made therefrom are disclosed. The polysiloxane elastomer containing liquid crystal lateral chain includes a polysiloxane backbone chain and a lateral chain formed by a liquid crystalline monomer and connected with the polysiloxane backbone chain, wherein the polysiloxane backbone chain is crosslinked by a crosslinking agent.

A lasing device includes an active layer comprising a cholesteric liquid crystal material and a laser dye, and a liquid crystal cell including spaced apart substrates defining a cell gap in which the active layer is disposed. The substrates include electrodes arranged to bias the active layer into an oblique helicoidal (Ch.sub.OH) state. At least one substrate of the liquid crystal cell is optically transparent for a lasing wavelength range of the device.