A diffractive optical element and method for fabricating the diffractive optical element are provided. The diffractive optical element includes a substrate, a first diffractive structure layer and a second diffractive structure layer. The substrate has a first surface and a second surface opposite to the first surface. The first diffractive structure layer is disposed on the first surface of the substrate. The second diffractive structure layer is disposed on the second surface of the substrate. In the method for fabricating the diffractive optical element, at first, the substrate is provided. Then, a first glue material layer/first semiconductor layer is formed and patterned on the first surface of the substrate. Thereafter, a second glue material layer/second semiconductor layer is formed and patterned on the second surface of the substrate.

Provided is an observation optical system used for observing an image displayed on an image display surface. The observation optical system includes, in order from an observation surface side to the image display surface side, a first lens having a positive refractive power, and a second lens having a positive refractive power. The first lens is a Fresnel lens, and a focal length f1 of the first lens and a focal length f2 of the second lens are each appropriately set.

Holographic and diffractive optical encoding techniques for forming reflection or transmission holograms. The encoding device includes a substrate having an interference pattern that can propagate light along a light propagation path from one side of the substrate to another side of the substrate. Furthermore, an optical element may be used to propagate light according to a four-dimensional light field coordinate system.

A structured optical surface and an optical imaging system including the structured optical surface is described. The structured optical surface includes a plurality of structures formed by an intersection of at least first and second Fresnel patterns, such that when the structured optical surface is incorporated in an optical imaging system comprising a pixelated display surface with at least one pixel comprising at least two sub-pixels spaced apart by a gap, the structured optical surface images the at least two sub-pixels onto an image surface as at least two corresponding imaged sub-pixels spaced apart by a corresponding imaged gap, and the structured optical surface diffracts light so that the diffracted light at least partially fills the imaged gap without substantially overlapping any of the at least two imaged sub-pixels.

A remote sensing system includes a primary beam configured to carry orbital angular momentum and characterized by a mode number (m), with the mode number (m) being a non-zero integer. The primary beam is configured to be directed at a target. A photon sieve is configured to receive a secondary beam emanating from the target. The secondary beam at least partially includes a portion of the primary beam. The photon sieve includes a plurality of holes forming one or more respective spiral patterns. The quantity of the respective spiral patterns in the photon sieve corresponds to the mode number (m) of the primary beam. The plurality of holes may be configured to have a minimum diameter such that the minimum diameter is greater than a predefined wavelength of the primary beam. The respective spiral patterns extend between a respective first hole and a respective final hole.

In the present invention, by providing a 3D holographic display system comprising a modulation apparatus configured to modulate light emitted from a light source into a light wave corresponding to a 3D image, an optical apparatus configured to propagate the light wave into the first plane, and a diffraction apparatus configured to multiplex the propagated light wave to extend viewing angle of the 3D holographic display, a limited viewing zone of the holographic display determined by the SLM pixel pitch, may be extended by optical methods, such as using diffractive optical elements (DOE) for spatial-division multiplexing (SDM).

Provided an imaging apparatus including a first optical device, a second optical device disposed such that light transmitted through the first optical device is incident on the second optical device, and a third optical device disposed such that light transmitted through the second optical device is incident on the third optical device, wherein at least one of the first optical device, the second optical device, and the third optical device includes a plurality of nanostructures, and heights of at least two nanostructures of the plurality of nanostructures are different from each other.

The invention relates optical devices, for example pixelated devices such as an optical device having a plurality of coloured pixels, each said pixel comprising a filter structure, the filter structure comprising: a first metallic layer; a dielectric layer over said first metallic layer; and a second metallic layer over said dielectric layer; wherein said second metallic layer comprises a nanostructured metallic layer having a lateral structure with features having at least one characteristic lateral dimension equal to or less than 1 m, and wherein said second metallic layer is structured to couple light incident on said second metallic layer into at least two absorption modes of the filter structure, one to either side of a target wavelength, such that said filter structure appears coloured at said target wavelength in reflected or transmitted light.

In various embodiments, the present disclosure provides devices, time-of-flight sensors, and optical sensor packages. One such device includes a light sensor, a first lens, and a second lens. The first lens is positioned along a light receiving path of the light sensor, and the first lens has a first surface and a second surface opposite the first surface. The second lens is positioned along the light receiving path and positioned between the first lens and the light sensor. The second lens has a third surface facing the second surface of the first lens and a fourth surface opposite the third surface. The fourth surface faces the light sensor. At least one of the first, second, third, and fourth surfaces is a Fresnel surface.

An optical device fabrication method includes removing semiconductor material from a semiconductor substrate to form a first curved surface and a second curved surface, forming a bonding material on the first curved surface, and selectively removing semiconductor material from at least one of the first and the second curved surfaces to form one or more subwavelength structures. The semiconductor substrate has a bandgap wavelength associated with a bandgap energy of the semiconductor material. The optical device refracts certain incident electromagnetic radiation and/or filters other electromagnetic radiation. The refracted radiation includes infrared wavelengths longer than the bandgap wavelength and the filtered radiation includes wavelengths shorter than the bandgap wavelength.