An optical device is provided that comprises a multi-order diffractive Fresnel lens (MOD-DFL) and an achromatizing compensation mechanism that reduces refractive dispersion created by the MOD-DFL, thereby reducing the focal range of the MOD-DFL. A method is also provided of using the optical device in an image processing system to obtain images of an object and processing the images to perform image enhancement.

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.

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 security device includes a plurality of diffractive surface elements arranged on a 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. An orientation of the diffractive surface elements in the first surface element group can be matched to each other wherein they make a first point of an associated symbol to be represented visible. A plurality of additional surface element groups each can make a respective additional point of the symbol to be represented visible. The symbol can include a sum of all points represented by the first surface element group and the plurality of additional surface element groups. A movement of the symbol can be perceived by the continuous change in an angle of incidence of the light or an observation angle.

Methods and systems for heating a space deployed membrane assembly are provided. The membrane assembly can include one or more framed sections. Each section can include a composite membrane having a membrane substrate and a transparent, electrically conductive resistive coating. The composite membrane is held within a frame. Electrically conductive bus bars are provided and are placed in intimate electrical contact with the resistive coating. The electrically conductive bus bars are generally arranged, on opposite sides of the perimeter of the membrane. A controller passes current between selected bus bars, with different bus bars operative to pass current between them at different times. The magnitude of the voltage applied to the bus bars, the location of the bus bars, the operational sequence of powering the bus bars, and the time over which current is passed between a selected pair of bus bars, are selected to provide substantially uniform time averaged heating of the membrane.

Provided in an illumination device including a display panel including a first surface configured to display an image, a second surface opposite to the first surface, a plurality of display pixels disposed between the first surface and the second surface, and a transmission window configured to transmit light incident on the second surface through the first surface, a light source disposed at the second surface of the display panel and configured to emit light to an object toward the display panel, and a light deliverer disposed between the light source and the display panel, the light deliverer configured to deliver the light emitted from the light source to the object as flood illumination through the transmission window.

Disclosed is a method for producing a multilayer Laue lens. The object to provide a method for producing a wedged MLL that can be operated over a large range of wavelengths, and which preferably requires only a linear stage to adjust the positions of the lens as the wavelength is changed, is achieved by providing a lens blank comprising a substrate element having a flat upper surface extending in a plane defined by orthogonal axes x, y, z, wherein x and z extend in the plane and y extends normal to the plane, a layered structure deposited on the upper surface of the substrate element in such a way that at least two different materials are layered upon one another in an alternating manner, wherein the y-extension of the layered structure is constant along the x-axis and varies along the z-axis within a ramp section where the y-extension of the layered structure increases from a starting point, where first particles of material of the layered structure are deposited on the upper surface of the substrate element, to a saturation point, where a maximum y-extension of the layered structure is reached; and slicing a lens out of the lens blank by slicing through the ramp section in parallel to the y-axis but not parallel to the x- and z-axes.

An optical element (100) and an optical module (200), relating to the technical field of optics. The optical element comprises a diffractive optical element (110), and a Fresnel lens (120) connected to the diffractive optical element (110), such that a light beam that passes through the Fresnel lens (120) and is then transmitted through the diffractive optical element (110) forms a preset pattern. The assembly cost and the assembly difficulty can be reduced, and miniaturization of the optical module (200) can be facilitated.

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.

A multilayer Laue lens (MLL) that can be operated over a large range of wavelengths which is achieved by providing a lens blank comprising a substrate element extending in a plane defined by orthogonal axes x, y, z, with a layered structure deposited on the upper surface with at least two different materials that are layered upon one another in an alternating manner, wherein the y-extension of the layered structure is constant along the x-axis and varies along the z-axis within a ramp section where the y-extension of the layered structure increases from a starting point, where first particles of material of the layered structure are deposited on the upper surface of the substrate element, to a saturation point, where a maximum y-extension of the layered structure is reached; and slicing a lens out of the lens blank.