An optical waveplate is provided. The optical waveplate includes a plurality of liquid crystal (“LC”) layers stacked together. At least one of the plurality of LC layers includes LC molecules that are in-plane switchable by an external field to switch the optical waveplate between states of different phase retardances.

A waveplate is provided. The waveplate includes a first liquid crystal (“LC”) layer including LC molecules that are in-plane switchable by an external field to switch the waveplate between states of different phase retardances. The waveplate includes a second LC layer and a third LC layer sandwiching the first LC layer. Azimuthal angles of effective refractive index ellipsoids of the second LC layer and the third LC layer are different.

An optical waveplate is provided. The optical waveplate includes a plurality of liquid crystal (LC) layers stacked together. At least one of the plurality of LC layers includes LC molecules that are in-plane switchable by an external field to switch the optical waveplate between states of different phase retardances.

A voltage-controllable output coupler for a laser, comprising: a liquid crystal cell that provides a change in birefringence in response to an applied voltage; and a polariser oriented with respect to the liquid crystal cell to collectively form a variable reflectance mirror for the laser; wherein output coupling of the laser is controllable by applying voltage to the liquid crystal cell for a switching interval to switch the variable reflectance mirror from high reflectance to low reflectance, and vice versa, thus actively Q-switching or cavity dumping the laser.

A liquid crystal Fresnel lens is provided. The liquid crystal Fresnel lens includes a liquid crystal cell and two polarizers. The liquid crystal cell includes: two transparent substrates having conducting layers disposed thereon with alignment layers, wherein an alignment pattern formed by the alignment layers are configured to provide multiple alignment domains in a Fresnel zones pattern, and wherein an easy axis of adjacent alignment domains are oriented at an angle relative to one another; and a ferroelectric liquid crystal layer disposed between the two transparent substrates, wherein the ferroelectric liquid crystal layer has a planar surface orientation and smectic layers perpendicular to the two transparent substrates. The liquid crystal cell is disposed between the two polarizers.

The invention relates to the field of optoelectronics, and may be used in devices and of visualization, displaying, storage and processing of information, in particular in projection displays, etc. Video projector consists of a liquid crystal micro display based on structure FLCoS, and an optical unit of reading the information formed in the structure FLCoS, containing a light source and projection optics, optically coupled to the structure FLCoS, and a screen, onto which the information is projected. As the electro-optical material the low-voltage ferroelectric liquid crystal (FLC) with compensated helix providing physically realizable, continuous, halftone, hysteresis-free modulation characteristic is used in the structure FLCoS. Lasers of red, green and blue radiation serve as the sources of light in three different color channels RGB. To destroy the ability of their radiation to the interference, a cell with FLC is inserted into the optical unit of information reading that implements fast electrically controlled spatial phase light modulation with a depth of , and in order to form on the screen the information blocks with a capacity of 10.sup.8 . . . 10.sup.9 pixels, with different geometric configurations a two-dimensional scanner is input, which optically coupled to the optical unit of information reading and to the screen. The technical result is an increase of frame rate, expanding the color gamut, brightness enhancement, noise reduction.