G03H1/0244

Method for manufacturing holographic blazed grating
09864113 · 2018-01-09 · ·

A method for fabricating a holographic blazed grating is provided. The method includes: coating a photoresist layer on a substrate; performing lithography on the photoresist layer to form a photoresist grating; performing vertical ion beam etching on the substrate by using the photoresist grating as a mask, to form a homogeneous grating by transferring a pattern of the photoresist grating onto the substrate; cleaning the substrate to remove remaining photoresist; performing tilted Ar ion beam scanning etching on the substrate by using the homogeneous grating as a mask, and etching different portions of the substrate by utilizing a obscuring effect of the homogeneous grating mask on the ion beam, to form a triangular groove shape of the blazed grating; and cleaning the substrate to obtain the holographic blazed grating.

Surface relief volume reflective diffractive structure
09864339 · 2018-01-09 · ·

A surface relief structure includes a recording medium configured to be structurally modified when exposed to interfering and non-interfering portions of radiation beams, the structurally modified recording medium including, when viewed in a two-dimensional cross-section along one of the axes of the recording medium a plurality of equally spaced steps of fine-sized periodicity superimposed upon a plurality of deep depressions of substantially coarse-sized periodicity. The structurally modified recording medium is configured to produce in reflection single and multiple colors in a broad spectral range when illuminated by a source of light.

LIGHT MODULATION ELEMENT AND INFORMATION RECORDING MEDIUM

A light modulation element reproduces a light image in a specific color other than iridescence where white light is incident, without a layer that selectively transmits or reflects a specific wavelength band, and clearly reproduces a desired light image by reducing an influence of 0th-order diffracted light, and an information recording medium including the same. The light modulation element includes a factor element that reproduces a light image by modulating a phase of incident reproduction light, and has an uneven surface. A maximum diffraction efficiency Dmax in a wavelength band of between 380 nm and 780 nm in wavelength distribution of first-order diffracted light and of negative first-order diffracted light with respect to diffraction efficiency for the factor element has a local maximum value with a full width at half maximum FWHM of 200 nm or less in wavelength distribution with respect to diffraction efficiency having the maximum diffraction efficiency.

DIFFRACTION SHEET AND METHOD FOR MANUFACTURING THE SAME, THREE-DIMENSIONAL DISPLAY DEVICE, LIGHT BEAM REPRODUCTION DEVICE, THREE-DIMENSIONAL SPATIAL DISPLAY SYSTEM, LIGHT BEAM REPRODUCTION METHOD, AND PROGRAM
20240411066 · 2024-12-12 · ·

A three-dimensional display device including a diffraction sheet including a transparent substrate, and a diffraction layer having a first diffraction pattern formed in a first array pattern and a second diffraction pattern formed in a second array pattern on the transparent substrate, the diffraction sheet measuring 10 inches or more in diagonal; one of a liquid crystal device having a plurality of pixels and a color filter having a plurality of types of color filters; and a light source. The first diffraction pattern and the second diffraction pattern are overlapped with the pixels or the color filters in a direction normal to the diffraction sheet with an amount of displacement being 1/10 or less of a pitch of the pixels or the color filters.

Optically variable security devices

An optical device is formed by hot stamping a demetallized hologram to an optically variable foil or to a coating of optically variable ink. In another embodiment a hologram is hot stamped to a banknote or document printed with a color-shifting ink.

ARBITRARY POLARIZATION-SWITCHABLE METASURFACES

An optical component comprises a metasurface comprising nanoscale elements. The metasurface is configured to receive incident light and to generate optical outputs. The geometries and/or orientations of the nanoscale elements provide a first optical output upon receiving a polarized incident light with a first polarization, and provide a second optical output upon receiving a polarized incident light with a second polarization that is different from the first polarization.

Diffraction structure transfer foil and forgery prevention medium using same
09827804 · 2017-11-28 · ·

Provided are diffraction structure transfer foil that further improves usefulness of the diffraction structure transfer foil in authenticity determination by allowing a greater variety of diffracted-light patterns to be observed, and a forgery prevention medium using the diffraction structure transfer foil. The diffraction structure transfer foil (21) includes a transfer foil substrate (1), a peeling-off protective layer (2) that is laminated on one surface of the transfer foil substrate (1), a laminated body for diffracted-light delivery (13a) that is laminated on the peeling-off protective layer (2), and an adhesive layer (9) that is laminated on the laminated body for diffracted-light delivery (13a). The laminated body for diffracted-light delivery (13a) includes a diffraction structure forming body in which a plurality of diffraction structures (4 and 7) are formed, and a reflective layer (5a or 8a) that is formed in accordance with each of the plurality of diffraction structures (4 and 7). A transmission density of one reflective layer (5a) of the plurality of reflective layers (5a and 8a) is in a range of 0.01 to 0.9, and a transmission density of the other reflective layer (8a) is 1.0 or greater.

HOLOGRAM, LIGHT-TRANSMISSIVE REFLECTOR PLATE, SCREEN, AND PROJECTION SYSTEM USING THEM

To provide a hologram, a light-transmissive reflector plate, a screen, and a projection system capable of achieving high transparency and allowing a projected image to be brightly and clearly reflected and observed.

A hologram 1 has a relief part, wherein the hologram 1 reflects a given white light incident thereon at a given angle from one side, while transmits a given white light incident thereon at a given angle from the other side, and diffraction efficiency for transmitted light and diffraction efficiency for reflected light differ from each other.

HOLOGRAPHIC DECORATED GLASS FOR SCREEN COLOR MATCHING
20250060705 · 2025-02-20 ·

Exemplary systems that may reduce or eliminate the visibility of a boundary between the displaying portions of the system and the non-displaying portions of the system are disclosed. An exemplary system includes a display screen including a plurality of pixels forming a first periodic structure and a frame surrounding at least a portion of the display screen. The frame may include a holographic structure having a second periodic structure. The first pitch of the first periodic structure may be within 0.5 percent to 20 percent of the second pitch of the second periodic structure.

Infrared laser holographic projector
09665065 · 2017-05-30 · ·

Systems and methods for infrared laser holographic projection. In one example, an optical apparatus includes a first laser source configured to generate a first laser beam having a first wavelength in an infrared spectral range and a holographic medium optically coupled to the laser source and having a transmittance range including the first wavelength. A diffraction pattern formed in the holographic medium encodes an input image and is configured to diffract the first laser beam responsive to being illuminated by the laser beam so as to construct an image in the infrared spectrum, the image being a reconstruction of the input image. The diffraction pattern may further be configured to diffract a second laser beam having a second wavelength in a visible spectral range to construct an image including a first portion in the infrared spectral range and a second portion in the visible spectral range.