The purpose of the present invention is to provide: elements, in particular, a display element and an optical element, which are obtained by controlling orientation of liquid crystals in a liquid crystal bulk without using a liquid crystal orientation film; and/or a photoreactive liquid crystal composition for manufacturing the elements. The present invention provides: a photoreactive liquid crystal composition comprising (A) a photoreactive polymer liquid crystal which includes a photoreactive side chain in which at least one type of reaction selected from the group consisting of (A-1) photocrosslinking and (A-2) photoisomerization occurs, and (B) a low molecular weight liquid crystal; and an optical element or display element which is formed having a liquid crystal cell including the composition.

The present invention relates to complex security elements based on recording materials for optical elements with refractive index modulation, in particular, holograms, which are subsequently coated with specific metallic nano-shaped metal particles, a method for their manufacture, in particular on a paper or on a plastic substrate and a security product obtainable using the security element. A further aspect of the invention is the use of such a security element for the prevention of counterfeit or reproduction of a document of value.

A display device includes an optical sensor configured to image a user eye, an image source configured to provide image light, a holographic film including a plurality of holograms, and a controller. Each hologram is recorded with a same reference beam but recorded differently so as to differently diffract image light received from the light source. The controller is configured to determine, via the optical sensor, a position of the user eye, and adjust, based on the determined position of the user eye, a state of the holographic film such that a particular hologram of the plurality of holograms diffracts image light to the position of the user eye.

Various embodiments set forth eye tracking systems. In some embodiments, an eye tracking system includes a polarization volume hologram (PVH) combiner having a rolling k-vector design that provides relatively wide coverage of users whose eyeglasses prescriptions can vary. The PVH combiner can further include (1) fiducial regions created by differential patterning that generate dark regions in images captured of an eye, and/or (2) multiple regions that diffract light at angles to produce different perspectives in the captured images. The dark regions and/or different perspectives can be used to calibrate eye tracking. In addition, the PVH combiner can include off-axis lens regions that generate glints for the eye tracking.

Improvements to gratings for use in waveguides and methods of producing them are described herein. Deep surface relief gratings (SRGs) may offer many advantages over conventional SRGs, an important one being a higher S-diffraction efficiency. In one embodiment, deep SRGs can be implemented as polymer surface relief gratings or evacuated periodic structures (EPSs). EPSs can be formed by first recording a holographic polymer dispersed liquid crystal (HPDLC) periodic structure. Removing the liquid crystal from the cured periodic structure provides a polymer surface relief grating. Polymer surface relief gratings have many applications including for use in waveguide-based displays.