An embodiment of the present disclosure provides a holographic optical element and a manufacturing method of a holographic optical element including holographic gratings, the manufacturing method including: a step (a) of forming a photosensitive substrate by coating one surface of a substrate with a photosensitive resin; and a step (b) of recording the holographic gratings by irradiating each of one surface and the other surface of the photosensitive substrate with laser light, wherein in the step (a), the photosensitive resin is applied so that a height of a photosensitive resin coating layer varies along a predetermined direction.

Provided is a display method for displaying an image based on a color original image. The display method includes guiding an image light corresponding to the color original image to a display position by an optical system, and deflecting a traveling direction of the image light to an observer and performing display by a diffraction optical element. At the time of displaying the color original image, the image light entering the first diffraction optical element includes a light entering at a first angle and a light entering at a second angle that is larger than the first angle, a chromaticity range of the image of the color original image at a position corresponding to the light entering at the first angle is limited to be close to a chromaticity range of the light entering at the second angle.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, an optically diffractive device includes: first and second diffractive components and a color-selective polarizer therebetween. The first diffractive component is configured to diffract a first color of light in a first polarization state incident at a first incident angle with a first diffraction efficiency at a first diffracted angle, and diffract a second color of light in a second polarization state with a diffraction efficiency substantially less than the first diffraction efficiency. The color-selective polarizer is configured to rotate the second polarization state of the second color of light to the first polarization state. The second diffractive component is configured to diffract the second color of light in the first polarization state with a second diffraction efficiency at a second diffracted angle substantially identical to the first diffracted angle.

Methods, apparatus, devices, and systems for displaying three-dimensional objects by individually diffracting different colors of light are provided. In one aspect, a system includes a display having a plurality of display elements and an optical device including at least two beam expanders configured to expand an input light beam in at least two dimensions to generate an output light beam to the display by diffracting the input light beam to adjust a beam size of the input light beam in the at least two dimensions, the input light beam including a plurality of different colors of light.

A method of manufacturing a Volume Bragg Grating (VBG) is provided, comprising providing a cylindrical bulk medium made of a transparent glass material and having a central axis along a longitudinal direction, and inscribing an interference pattern in the cylindrical bulk medium. The interference pattern has a plurality of grating fringe elements distributed along a line parallel to the central axis. The method further includes rotating the cylindrical bulk medium about the central axis during said inscribing, thereby azimuthally extending the grating fringes elements. There is further provided a VBG manufactured according to such a method, the use of such a VBG in a CPA system of cladding-pumped fiber laser.

A system includes a light outputting element configured to output a first beam propagating toward a beam interference zone from a first side of the beam interference zone. The system also includes a reflective assembly configured to reflect the first beam back as a second beam propagating toward the beam interference zone from a second side of the beam interference zone. The first beam and the second beam interfere with one another within the beam interference zone to generate a polarization interference pattern.

An optical device having suppressed rainbow effect is provided. The optical device includes a light source configured to generate an image light, an optical combiner coupled with the light source and configured to direct the image light to an eye-box of the optical device, and a dimming element disposed at the optical combiner. The optical combiner includes at least one diffractive element. The optical combiner has a first side facing the eye-box and an opposing second side facing a real world, and the dimming element is disposed at the second side of the optical combiner. The dimming element is configured to receive a light from the real world and significantly attenuate an intensity of the light having an incidence angle in a predetermined range.

Recording a volume Bragg grating is effectuated by a recording medium formed from a matrix polymer precursor including a controlled radical reactive group, a photoactive base monomer, and a photoinitiator system more reactive with the photoactive base monomer than the controlled radical reactive group in the presence of an excitation source, and a photoredox catalyst. The medium is cured thereby forming a support matrix from the matrix polymer precursor. Exposure to the excitation source through a pattern causes the photoinitiator to polymerize the base monomer, forming a latent grating of the Bragg grating. The latent grating has bright and dark fringes determined by the pattern. The concentration of polymerized base polymer is higher in the bright fringes than in the dark fringes. The exposing causes a portion of the matrix to diffuse into the dark fringes. The support matrix has a lower refractive index than the polymerized photoactive base monomer.

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.

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.