Abstract: Disclosed herein is a liquid crystal lens with a variable focal length. The gradient profile of the liquid crystals molecules that causes the gradient profile of the refractive index is achieved by inducing non-uniformly distributed anchoring energy and an external electric or magnetic field applied to the liquid crystal layer. Unlike existing electrically controlled liquid crystal lens, the external electric or magnetic field has a uniform spatial distribution within the liquid crystal layer. The focal length of the liquid crystal lens is controlled via the non-uniformly distributed anchoring energy and by varying the uniformly distributed electric or magnetic field.

Abstract: A liquid crystal optical device that includes a first substrate layer that is substantially flat and a second substrate layer that is substantially flat and parallel to the first substrate layer. The liquid crystal optical device further includes a layer of cholesteric liquid crystal disposed between the first substrate layer and the second substrate layer, where the layer of cholesteric liquid crystal is arranged in domains, each domain having a helical axis, wherein the helical axes of the domains have a plurality of orientations relative to an orientation of the first and second substrate layers, and where a wavefront of a light wave having a wavelength within a range of wavelengths changes after reflecting from the layer of cholesteric liquid crystal.

Abstract: Disclosed herein is a liquid crystal lens with a variable focal length. The gradient profile of the liquid crystals molecules that causes the gradient profile of the refractive index is achieved by inducing non-uniformly distributed anchoring energy and an external electric or magnetic field applied to the liquid crystal layer. Unlike existing electrically controlled liquid crystal lens, the external electric or magnetic field has a uniform spatial distribution within the liquid crystal layer. The focal length of the liquid crystal lens is controlled via the non-uniformly distributed anchoring energy and by varying the uniformly distributed electric or magnetic field.

Abstract: A method for simultaneous measuring a thickness of a liquid crystal layer and an average refractive index of the said liquid crystal in sealed liquid crystal cell is disclosed. The method is based on analysis of spectral positions of maxima and minima of interference oscillations, their magnitudes and their envelope in the spectrum of light mirrored by the liquid crystal cell at several different angles-of-incidence. The method is applicable to cells filled with different liquid crystals including cholesterics and smectics.

Abstract: A method for simultaneous measuring a thickness of a liquid crystal layer and an average refractive index of the said liquid crystal in sealed liquid crystal cell is disclosed. The method is based on analysis of spectral positions of maxima and minima of interference oscillations, their magnitudes and their envelope in the spectrum of light mirrored by the liquid crystal cell at several different angles-of-incidence. The method is applicable to cells filled with different liquid crystals including cholesterics and smectics.