Optical metasurface with sub-hogels
A sub-hogel configuration for a high-definition light field display that can be used in the design of optical device and three-dimensional light field display technology. Three-dimensional holographic pixels (hogels) composed of monochromatic sub-hogels and a designed metasurface act as a directional optical element for a light field display. The sub-hogel structure design and method is suited for an achromatic metasurface to provide directional pixels for multiple view light field colored displays.
1. An optical device comprising:
a hogel array comprising a plurality of sub-hogel elemental images, each sub-hogel elemental image partitioned into a plurality of monochromatic sub-hogels each comprising a plurality of monochromatic sub-pixels, each monochromatic sub-hogel having a color-channel specific elemental image; and
a directional optical element to direct light from the sub-pixels, the directional optical element partitioned into a plurality of color regions, each color region designed to direct light of a specific color, the monochromatic sub-hogels and the plurality of color regions configured such that the plurality of monochromatic sub-pixels are aligned with the color region of the directional optical element designed to direct light of the specific color of the monochromatic sub-pixels.
2. The optical device of claim 1 wherein the directional optical element is a metasurface.
3. The optical device of claim 2 wherein the metasurface comprises nanostructures.
4. The optical device of claim 3 wherein the nanostructures comprise titanium dioxide.
5. The optical device of claim 3 , wherein the nanostructures are birefringent nanostructures of a fixed size.
6. The optical device of claim 3 , wherein the nanostructures are different for each color region.
7. The optical device of claim 6 , wherein the nanostructures have a single height per color region.
8. The optical device of claim 6 , wherein the nanostructures have a single height across all color regions.
9. The optical device of claim 2 , wherein the metasurface is divided into a plurality of segments to accommodate the plurality of color regions such that each of the plurality of segments has a corresponding cluster of like colored sub-pixels.
10. The optical device of claim 9 , wherein each of the plurality of segments is tailored to a specific wavelength of light.
11. The optical device of claim 10 , wherein the specific wavelength of light is red light, blue light, or green light.
12. The optical device of claim 1 wherein each of the monochromatic sub-pixels is individually addressable.
13. The optical device of claim 1 wherein the plurality of monochromatic sub-hogels comprise at least one monochromatic red sub-hogel, at least one monochromatic green sub-hogel, and at least one monochromatic blue sub-hogel.
14. The optical device of claim 1 wherein each monochromatic sub-hogel comprises fewer monochromatic sub-pixels than can individually be discerned by a human eye.
15. The optical device of claim 1 wherein each monochromatic sub-hogel has between 2 and 144 monochromatic sub-pixels.
16. The optical device of claim 1 wherein each sub-pixel is less than 10 μm 2 .
17. The optical device of claim 1 wherein the monochromatic sub-pixels in each monochromatic sub-hogel are arrayed in a square configuration, rectangular configuration, or radial configuration.
18. The optical device of claim 1 wherein the directional optical element is a geometric metasurface, Pancharatnam-Berry metasurface, an inverse design metasurface, a dispersive phase compensating metasurface, or a combination thereof.
19. The optical device of claim 1 wherein the optical device is a light field display.