G02B5/203

Multilayered optical security device

A multilayered optical security device has a resonant waveguide grating (RWG) layer on an under layer having a hologram. The RWG layer has plural RWGs for generating one or more patterns. Each RWG has first and second RWG portions, with diffraction gratings of different grating periods, for light coupling-in and coupling-out, respectively. Using the RWGs minimizes interference to a holographic image generated by the under layer. This advantage is especially useful when the holographic image carries digital data such as in digital holographic encryption where an encrypted hologram is used in the under layer. The digital data may contain biometric information such as a fingerprint. In each RWG portion of an individual RWG, scattering elements in a grating are curved to thereby enhance an angular tolerance in azimuthal angle during observing the patterns by an observer while the individual RWG is still selective in elevation angle.

REFLECTIVE COLOR PIXEL BASED ON LOSSY METAL
20220179142 · 2022-06-09 ·

The present disclosure relates to a reflective color pixel including a dielectric grating formed on a lossy metal substrate.

Displaying three-dimensional objects

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 configured to diffract a plurality of different colors of light to the display. The optical device is configured such that, when the plurality of different colors of light is incident on the optical device, the optical device separates light of individual colors of the different colors while suppressing crosstalk between the different colors.

Achromatic metasurface optical components by dispersive phase compensation

Multi-wavelength light is directed to an optic including a substrate and achromatic metasurface optical components deposited on a surface of the substrate. The achromatic metasurface optical components comprise a pattern of dielectric resonators. The dielectric resonators have nonperiodic gap distances between adjacent dielectric resonators; and each dielectric resonator has a width, w, that is distinct from the width of other dielectric resonators. A plurality of wavelengths of interest selected from the wavelengths of the multi-wavelength light are deflected with the achromatic metasurface optical components at a shared angle or to or from a focal point at a shared focal length.

MEMS WAVELENGTH SELECTABLE SWITCH FOR ADAPTIVE WAVELENGTH FILTERING
20220146815 · 2022-05-12 ·

A MEMS-based Wavelength Selectable Switch (WSS), used classically for demultiplexing fiber optic communications, is re-purposed to act as a filter. A light emitter provides a light beam with its wavelength detected by a wavelength detector. A light condenser directs reflected light from the light emitter to an input of the WSS. The WSS is controllable to provide a selected wavelength band to a selected output of the WSS, where it is detected by a photodetector. Other wavelengths are discarded by the WSS at other outputs. A controller is configured to control the WSS to select the selected wavelength band based on a detected wavelength from the wavelength detector.

OPTICAL MEMBER AND IMAGING APPARATUS

There are provided an optical member and an imaging apparatus. An optical member includes a plurality of aperture regions which transmit a ray of an optical system and include a first aperture region and a second aperture region and of which the first aperture region and the second aperture region are adjacent to each other, a plurality of optical filters disposed in the first aperture region and the second aperture region transmit light having at least a part of wavelength ranges different from each other, a plurality of polarizing filters disposed in the first aperture region and the second aperture region have polarization directions different from each other, and a ray incidence-reduction part that reduces incidence of a ray, which is incident on the first aperture region, on at least one of the optical filter or the polarizing filter disposed in the second aperture region.

Polarization spectral filter, polarization spectral filter array, and polarization spectral sensor

Provided is a polarization spectral filter, including: a first reflector and a second reflector disposed to face each other in a first direction; and a grating layer disposed between the first reflector and the second reflector. The grating layer includes a plurality of first grating elements and a plurality of second grating elements, the plurality of first grating elements and the plurality of second grating elements being alternately arranged in a second direction perpendicular to the first direction. The plurality of first grating elements include a first dielectric material having a first refractive index. The plurality of second grating elements include a second dielectric material having a second refractive index different from the first refractive index.

Reconstructing objects with display zero order light suppression

Methods, apparatus, devices, and systems for reconstructing three-dimensional objects with display zero order light suppression are provided. In one aspect, a method includes illuminating a display with light, a portion of the light illuminating display elements of the display, and modulating the display elements of the display with a hologram corresponding to holographic data to diffract the portion of the light to form a holographic scene corresponding to the holographic data, and to suppress display zero order light in the holographic scene. The display zero order light can include reflected light from the display.

HOLOGRAPHIC OPTICAL ELEMENT AND METHOD OF FORMING THEREOF
20210364686 · 2021-11-25 ·

There is provided a holographic optical element including: a hologram portion including a plurality of groups of unit regions, each group of unit regions of the hologram portion being configured to produce a respective holographic image under a respective light illumination having a respective predetermined wavelength; and a colour filter portion formed on the hologram portion, the colour filter portion including a plurality of groups of unit regions, each group of unit regions of the colour filter portion being arranged on a corresponding group of the plurality of groups of unit regions of the hologram portion, whereby the plurality of groups of unit regions of the colour filter portion is spatially arranged to form a predetermined colour image. There is also provided a method of forming the holographic optical element. There is further provided an article having optical security incorporated therein.

3-DIMENSIONAL VIEWING DEVICE WITH STEREOSCOPIC AFFECT AND INTERCHANGEABLE IMAGE DISCS AND COMPONENTS
20210349330 · 2021-11-11 ·

The invention of the current application is directed to a 3-dimensional viewing device with stereoscopic affect including a main linear body including at least one inner lining layer, and a mirror assembly. The at least one inner lining is positioned within the main linear body and the mirror assembly is positioned inside the main linear body where the perimeter of the mirror assembly is surrounded by the at least one inner lining. The mirror assembly includes at least two mirrors. The 3-dimensional viewing device with stereoscopic affect also includes an image holder assembly including a gear assembly, and an endcap including a viewing hole. The endcap is attached to a first end of the main linear body and the second end of the main linear body at least partially inserts into an opening in the image holder assembly.