Gratings may be used in waveguides. Deep surface relief gratings (SRGs) may offer many advantages over conventional SRGs, an important one being a higher S-diffraction efficiency. 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.

Several unique configurations for interferometric recording of volumetric phase diffractive elements with relatively high angle diffraction for use in waveguides are disclosed. Separate layer EPE and OPE structures produced by various methods may be integrated in side-by-side or overlaid constructs, and multiple such EPE and OPE structures may be combined or multiplexed to exhibit EPE/OPE functionality in a single, spatially-coincident layer. Multiplexed structures reduce the total number of layers of materials within a stack of eyepiece optics, each of which may be responsible for displaying a given focal depth range of a volumetric image. Volumetric phase type diffractive elements are used to offer properties including spectral bandwidth selectivity that may enable registered multi-color diffracted fields, angular multiplexing capability to facilitate tiling and field-of-view expansion without crosstalk, and all-optical, relatively simple prototyping compared to other diffractive element forms, enabling rapid design iteration.

An apparatus and method for displaying holograms. A compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.

We describe a window assembly comprising: a window pane comprising a glass or plastic sheet; and a layer of holographic recording medium attached to said glass or plastic sheet; wherein said layer of holographic recording medium has recorded within the medium a volume hologram configured to direct light incident onto said glass or plastic sheet to propagate within a thickness of said glass or plastic sheet. In embodiments the volume hologram is fabricated by recording a transmission hologram and shrinking the recorded hologram to convert the transmission hologram to an edge-directing hologram configured to direct light in a direction to be totally internally reflected within the window pane, for example at greater than 40, 50, 60, 70, 75 or 80 to a normal to the surface of the hologram.

Described herein are devices, compositions, and methods for improving color discernment. In particular, devices and methods for correcting color blindness comprising a hologram that enhances the ability to distinguish a desired first bandwidth by decreasing the transmission of a second bandwidth. Advantageously, the device appears not tinted to outside observer.

The disclose relates to a method for producing volume reflection holograms with substrate-guided reconstruction beams and/or substrate-guided diffracted beams in a single-beam set-up, including the steps of (i) providing at least one laser beam source producing a recording beam having a first wave vector (ii) providing a holographic recording medium on a transparent substrate, the substrate having a first flat side facing the at least one laser beam source and a second flat side facing away from the at least one laser beam source, where the holographic recording medium is arranged on the first flat side or on the second flat side, (iii) providing a reflector arrangement arranged on the second flat side of the substrate.

Hybrid white-light viewable holograms and methods for making them. The holograms are hybrid reflection holograms made using the diffractive structures or gratings of a holographic object such as a transmission hologram or holographic optical element (HOE). The wavefronts of the diffractive structures are converted into a reflection hologram by scanning them with a coherent light source having a profiled narrow beam. The hybrid reflection hologram can exhibit display parameters including the multiple colors, solidity, and color stability of white light reflection holograms, the diffractive color shifting of a white light transmission hologram, three dimensional imaging and a wide variety of dynamic changes. Different areas or images with each of these effects can be combined in a single hologram. These hybrid reflection holograms are ideal for security and forgery prevention applications.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optical device includes: a first optically diffractive component including a first diffractive structure configured to diffract a first color of light having a first incident angle at a first diffracted angle, a second optically diffractive component including a second diffractive structure configured to diffract a second color of light having a second incident angle at a second diffracted angle, a first reflective layer configured to totally reflect the first color of light having the first incident angle and transmit the second color of light, and a second reflective layer configured to totally reflect the second color of light having the second incident angle. The first reflective layer is between the first and second diffractive structures, and the second diffractive structure is between the first and second reflective layers.

Mastering systems and methods of fabricating waveguides and waveguide devices using such mastering systems are described. Mastering systems for fabricating holographic waveguides can include using a master to control the application of energy (e.g. a laser, light, or magnetic beam) onto a liquid crystal substrate to fabricate a holographic waveguide into the liquid crystal substrate. Mastering systems for fabricating holographic waveguides in accordance with embodiments of the invention can include a variety of features. These features include, but are not limited to: chirp for single input beam copy (near i.e. hybrid contact copy), dual chirped gratings (for input and output), zero order grating for transmittance control, alignment reference gratings, 3:1 construction, position adjustment tooling to enable rapid alignment, optimization of lens and window thickness for multiple RKVs simultaneously, and avoidance of other orders and crossover of the diffraction beam.

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.