An optical sensor for imaging a biometric object includes: a cover layer transparent to light reflected off the biometric object; an optical layer, disposed below the cover layer, having a plurality of diffractive optical elements; and a sensing layer, having a plurality of sensing elements disposed below the optical layer, each of the sensing elements being configured to detect light from the biometric object. The plurality of diffractive optical elements of the optical layer are configured to direct light from the biometric object to the plurality of sensing elements.

A holographic substrate-guided wave-based see-through display has a microdisplay, capable of emitting light in the form of an image. The microdisplay directs its output to a holographic optical element, capable of accepting the image from the microdisplay, and capable of transmitting the light. The holographic optical element couples its output to an elongate substrate, capable of accepting the light from the holographic optical element at a first location, and transmitting the light along a length of the substrate by internal reflection to a second location, the elongate substrate being capable of transmitting the accepted light from the second location. The substrate couples out what it receives to a transparent holographic optical element, capable of accepting the light transmitted from the substrate and transmitting it to a location outside of the holographic optical element as a viewable image.

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).

A security device includes a plurality of diffractive surface elements arranged on a carrier element. A surface covered by the diffractive surface elements on the carrier element can occupy at least a partial region of the carrier element. Each individual diffractive surface element can have a three-dimensional surface structure. A portion of the plurality of the diffractive surface elements can form a first surface element group including the portion of the plurality of diffractive surface elements, and an orientation of the diffractive surface elements in the first surface element group can be matched to each other wherein together they make a single first image point of an associated first symbol to be represented visible to an observer under particular observation conditions.

A serpentine integrated grating spectrometer includes a serpentine delay line and a plurality of grating couplers. The serpentine delay line includes a plurality of parallel waveguide segments that are coplanar in a delay-line plane. The serpentine delay line serially connects each of the plurality of grating couplers. Each of the plurality of grating couplers (i) is located at a respective one of the plurality of parallel waveguide segments, and (ii) direct light propagating in the serpentine delay line out of the delay-line plane. The plurality of waveguide segments is M in number and impart a total group delay time ry on light propagating therethrough. Each of the plurality of grating couplers impart a grating coupler delay t.sub.x on light propagating therethrough that exceeds (t.sub.y/M), the time delay for a single segment of the M parallel segments.

A diffractive optical element configured as a lens having such an aperture function that causes light incident onto such lens to form a multiplicity of focal points (whether real or virtual) that do not lie along the same axis transverse to the surface of such lens, thereby simultaneously forming a multiplicity of spatially-independent optical images distributed transversely to a normal drawn to a surface of such lens. A method of using such diffractive optical element.

An electromagnetic radiation sorting device comprises an image sensor having an imaging plane; a substrate layer positioned adjacent to and spaced a distance from the imaging plane of the image sensor such that the imaging plane of the image sensor is in the Fresnel near field; and a functional layer coupled to the substrate layer, the functional layer having a structure that is configured to sort incoming electromagnetic radiation according to frequency by imparting orbital angular momentum and linear momentum on the incoming electromagnetic radiation.

Provided is a thin light unit for a display device that includes, for example, a high refraction film including an inclined portion at a first side of the high refraction film and a flat portion extended from the inclined portion to a second side of the high refraction film; a second member on the inclined portion at the first side of the high refraction film and having a first width; a first member on the flat portion in a middle of the second side of the high refraction film and separated from the second member; a third member on the flat portion and having the first width; and a light source adjacent to the first member at a side of the flat portion.

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.

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.