Abstract: Provided are an optical element that can make the brightness of light emitted from a light guide plate uniform, a light guide element, and an image display device. The optical element includes a patterned cholesteric liquid crystal layer that is obtained by immobilizing a cholesteric liquid crystalline phase, in which the patterned cholesteric liquid crystal layer has a liquid crystal alignment pattern in which a direction of an optical axis derived from a liquid crystal compound changes while continuously rotating in at least one in-plane direction, and the patterned cholesteric liquid crystal layer has regions having different pitches of helical structures in a plane.

Abstract: An article is described herein that includes: a translucent substrate comprising opposing major surfaces; and an optical film structure disposed on a first major surface of the substrate, the optical film structure comprising an outer surface and a plurality of periods such that each period comprises an alternating low refractive index layer and high refractive index layer. The article exhibits a hardness of 10 GPa or greater measured at an indentation depth of about 100 nm by a Berkovich Indenter Hardness Test. Further, the article exhibits a single side average photopic light reflectance of at least 50% of non-polarized light as measured at the outer surface from near-normal incidence to an incident angle of 60 degrees over a portion of at least 10 nm within the visible spectrum. In addition, each low refractive index layer comprises SiO2 or doped-SiO2 and each high refractive index layer comprises AlOxNy, SiOxNy, SiuAlvOxNy, SiNx or ZrO2.

Abstract: An apparatus and method for detecting edges or for seam tracking when machining workpieces by means of a laser beam, e.g. joining or cutting. The present invention provides an apparatus for seam tracking of the process in the laser material processing, comprising at least two separate illumination elements, each emitting differently polarized light and a polarization camera.

Abstract: An embodiment according to the invention provides an optical filter that combines narrow spectral bandwidth and high rejection of out-of-band radiation with a wide acceptance angle. These filters are based on the nanoscale engineering of materials (“metamaterials”) that possess predefined birefringence determined by a combination of their geometry and material composition. These metamaterials are combined into a functional optical filter that can exhibit true zero crossing, with acceptance angle effectively decoupled from bandwidth, at practically any wavelength of interest.

Abstract: There is provided a light-guide, compact collimating optical device, including a light-guide having a light-waves entrance surface, a light-waves exit surface and a plurality of external surfaces, a light-waves reflecting surface carried by the light-guide at one of the external surfaces, two retardation plates carried by light-guides on a portion of the external surfaces, a light-waves polarizing beamsplitter disposed at an angle to one of the light-waves entrance or exit surfaces, and a light-waves collimating component covering a portion of one of the retardation plates. A system including the optical device and a substrate, is also provided.

Abstract: A method for polarizing an electromagnetic wave having a frequency of not less than 0.1 THz and not more than 0.8 THz using a polarizer includes steps (a) and (b). The step (a) includes preparing the polarizer. The polarizer includes: a sapphire single crystalline layer; and a CaxCoO2 crystalline layer. The CaxCoO2 crystalline layer is stacked on the sapphire single crystalline layer, a surface of the CaxCoO2 crystalline layer has a (100) plane orientation and the CaxCoO2 crystalline layer has a thickness of not less than 2 micrometers and not more than 20 micrometers. The step (b) includes irradiating the polarizer with the electromagnetic wave having a frequency of not less than 0.1 THz and not more than 0.8 THz to output an output wave having only a component parallel to a c-axis direction of the sapphire single crystalline layer.

Abstract: An optical sheet including a plurality of optical anisotropic films is provided. The optical anisotropic films of the optical sheet are alternately stacked on one another. Each optical anisotropic film has a plurality of main axis refractive indexes nx, ny and nz. The main axis refractive indexes nx and ny are in-plane main refractive indexes, and the main axis refractive index nz is a thickness-wise refractive index. The main axis refractive index nx is the minimum or the maximum among the main axis refractive indexes nx, ny and nz. Each optical anisotropic film has an optcial axis, and a direction of the optical axis is the same to a main axis direction of the main axis refractive index nx. The optical axes of the optical anisotropic films sequentially rotates along a predetermined in a thickness direction, and a totally rotation angle thereof is greater than or equal to 360 degrees.

Abstract: A polarization-sensitive infrared image sensor (also termed a snapshot polarimeter) utilizing a 2-D array of polarizers to filter infrared light from a scene according to polarization, and a 2-D array of photodetectors (i.e. a focal plane array) to detect the filtered infrared light and generate polarization information which can be used to form a polarization-sensitive image of the scene. By forming each polarizer on an optical fiber in a fiber optic faceplate, the polarizers can be located facing a 2-D array of retarders to minimize diffraction effects of the infrared light. The optical fibers also guide the filtered infrared light to the photodetectors to reduce cross-talk in the polarization information. The polarizers can be formed as wire grid polarizers; and the retarders can be formed as subwavelength surface-relief gratings.

Abstract: A polarization conversion element having plural polarization separation sections and plural phase modulation sections is disclosed. A light flux is separated into transmission light (P polarization) and reflection light (S polarization) by being input to a polarization separation section. The reflection light reflected at the polarization separation section is output in the same direction as that of the transmission light by being reflected again at an adjacent polarization separation section at a different position from a position where a light flux is input to the adjacent polarization separation section. The phase modulation section is disposed on an optical path of the transmission light or the reflection light and output light becomes the same polarization.