We create planar-periodic alignment in nematic liquid crystal (LC) cell by using a command layer of azo-dye molecules directly deposited on the cell substrates and exposed with two interfering laser beams of opposite circular polarizations. Permanent high efficiency polarization gratings are thus created. The diffraction efficiency of those gratings is controlled by a uniform electric field applied across the cell. The electro-optical properties of such polarization gratings are studied. Obtained gratings can be used for electrically controlled discrimination and detection of polarized components of light.

Electrically variable gradient index liquid crystal lens is developed that uses flat uniform liquid crystal layer and electrodes. The spatial modulation of the electric field across the lens aperture is obtained by the modulation of the effective dielectric constant of an integrated doublet lens structure. The dielectric constants of two materials, composing the doublet, are chosen to be different at electrical driving frequencies, while their optical refractive indexes are the same, hiding thus the structure from the optical point of view. This "hidden layer" approach decouples the electrical and optical functions of that structure, increases significantly the performance of the lens and enables new functionalities. The technical performance and various driving schemes of the obtained lens are presented and analyzed.

We investigate the electro-optical properties of polymer stabilized nematic liquid crystals produced by in situ photopolymerization technique using Gaussian laser beam. The distribution of refractive index in such structure under the action of a homogeneous electric field reveals a non-homogeneous lens-like character, approximately reproducing the intensity transverse distribution in the photopolymerizing beam.

This work explores the use of photoactive elastomers as elastic holographic materials. Holographic gratings were recorded on stretched films of an azobenzene elastomer, which is composed of a side‐chain liquid‐crystalline polymer with azobenzene mesogens, grafted to the rubbery polybutadiene block of a styrene–butadiene–styrene (SBS) triblock copolymer. The grating‐formation dynamics measurements revealed the formation of two gratings of different natures resulting from the coupled mechanical and optical effects. A first grating, formed quickly upon exposure, is due to the photoisomerization of oriented azobenzene groups. A second grating, developed at longer exposure times, may originate from changes in the anisotropic structure of the SBS matrix, which is induced by the photochemical phase transition of azobenzene mesogens. The first grating is unstable, but the second grating remains in relaxed films. Both mechanisms can be enhanced by deformation of the film.

We report on the observation of giant relief modulation in amorphous chalcogenide As2S3 glass under polarization modulated near band gap light illumination. We show that these periodic modulations are created as a result of the photoinduced mass transport despite the very low and uniform intensity light illumination. A phenomenological model, based on a photoinduced alignment of anisotropic microvolumes within the glass, is proposed to explain the phenomenon.

A mobile phone camera with an innovative electrically tunable liquid crystal lens (TLCL) concept is demonstrated. We first report the comparative theoretical and experimental analyses of the performance of a traditional "modal control" TLCL versus a TLCL using a floating (unpowered) transparent electrode (FTE). It is shown that the appropriate choice of voltage and frequency values of the driving electric signal may improve significantly (almost twice) the optical quality of the lens using the FTE. Exceptionally low spherical aberrations of the lens (< λ/10 for up to 10 diopters of optical power) and high modulation transfer functions of a mobile phone camera (using those lenses for autofocus function) are demonstrated in a very simple operation mode (frequency tuning of the lens' optical power at a fixed driving voltage). The capacity of the camera to perform high quality long distance photography and near distance bar code recognition within a short autofocus convergence time are demonstrated.

Polarization gratings were recorded in amorphous As2S3 chalcogenide thin films in three orthogonal recording configurations. The analysis of polarization discrimination properties of such vector gratings revealed a poor performance. It was shown that the main reason for this is the presence of nondesired scalar modulation of the same period. An exception is (s+p) recording configuration, where a pure polarization grating may be obtained even for relatively high photoexposures.

Additional electrical impedance is introduced in a liquid crystal lens by adding a floating (nonconnected) electrode. This enables excellent optical quality in a very simple operation mode (frequency tuning of the lens' optical power at a fixed driving voltage). The comparative analysis of this lens confirms its suitability for mobile imaging applications.