A fiber grating device of low cost and arbitrary length is formed on a portion of a portion or the entirety of a highly elastic fiber optic core having a low Young's modulus of elasticity by causing elongation of the fiber optic core and forming or depositing a hard skin or cladding on the elongated fiber optic core. When the stress is then released, the hard skin or cladding buckles (including elastic or plastic deformation or both) to form wrinkles at the interface of the fiber optic core and the hard skin or cladding which are oriented circumferentially and highly uniform in height and spacing which can be varied at will by choice of materials, stretching, and thickness and composition of the cladding. Since the elastic elongation of the fiber optic core portion may be 200% or greater, an unprecedented measurement range is provided.

Antireflection coatings for metasurfaces are described herein. In some embodiments, the metasurface may include a substrate, a plurality of nanostructures thereon, and an antireflection coating disposed over the nanostructures. The antireflection coating may be a transparent polymer, for example a photoresist layer, and may have a refractive index lower than the refractive index of the nanostructures and higher than the refractive index of the overlying medium (e.g., air). Advantageously, the antireflection coatings may reduce or eliminate ghost images in an augmented reality display in which the metasurface is incorporated.

In example embodiments, a diffraction grating includes a substrate having an outer surface, the substrate having a first refractive index. A plurality of grating elements are provided on the substrate. The grating elements may have a step-like structure. In some embodiments, each grating element includes a stepped channel that is inset into the substrate. The stepped channel has a second refractive index greater than the first refractive index. In some embodiments, the stepped channel is a two-step channel having a first step along the outer surface of the substrate and a second step extending inward from the first step. In some embodiments, the first step has a greater width than the second step.

The present invention provides a method and apparatus for fabricating a grating on a silicon substrate, and the resulting grating device. In some embodiments, the apparatus method includes providing a silicon substrate; growing a diamond layer on the substrate; removing most of the silicon substrate and polishing an obverse face of the silicon to leave a very thin layer of polished silicon on the diamond layer; depositing a stack on the diamond layer, wherein the stack includes a plurality of pairs of dielectric layers on the thin layer of polished silicon, wherein each pair of the plurality of pairs of dielectric layers includes a first layer having a first index of refraction value and a second layer having a second index of refraction value that is different than the first index of refraction value; and forming a diffraction grating on an outer surface of the stack.

A laminated diffractive optical element includes a first resin layer having a first lattice shape and a second resin layer having a second lattice shape. The first resin layer and the second resin layer are laminated in this order on a first substrate so that the lattice shapes oppose each other. The first resin layer contains a resin and transparent conductive particles. The transparent conductive particles have an average particle size of 1 nm to 100 nm. A ratio of a polymer of an energy curable resin raw material having a long diameter of 1 μm to 10 μm in the first resin layer is 70 pieces/mm.sup.3 or less.

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.

Embodiments described herein relate to methods and apparatus for forming gratings having a plurality of fins with different slant angles on a substrate and forming fins with different slant angles on successive substrates using angled etch systems and/or an optical device. The methods include positioning portions of substrates retained on a platen in a path of an ion beam. The substrates have a grating material disposed thereon. The ion beam is configured to contact the grating material at an ion beam angle ϑ relative to a surface normal of the substrates and form gratings in the grating material.

The invention relates to a Bragg mirror comprising a portion (110) of ribbon (100) having a refractive index n1, corrugations (112) having a refractive index n3 and a separation layer (111) separating the ribbon (100) from the corrugations (112) and having a refractive index n2, such that n2<n3 and n2<n1. The invention also relates to a method for producing such a mirror.

The disclosure provides a method that includes filling a cavity in a substrate with a second material, wherein the substrate includes a first material. The method also includes using galvanic and/or chemical deposition of a third material to apply an overcoating to a first surface of the substrate in a region of the cavity. The method further includes removing the second material from the cavity. In addition, the method includes, before or after removing the second material from the cavity, applying a reflective layer to the overcoating. The disclosure also provides related optical articles and systems.

Various embodiments provide an optical lens that includes wafer level diffractive microstructures. In one embodiment, the optical lens includes a substrate, a microstructure layer having a first refractive index, and a protective layer having a second refractive index that is different from the first refractive index. The microstructure layer is formed on the substrate and includes a plurality of diffractive microstructures. The protective layer is formed on the diffractive microstructures. The protective layer provides a cleanable surface and encapsulates the diffractive microstructures to prevent damage and contamination to the diffractive microstructures. In another embodiment, the optical lens includes a substrate and an anti-reflective layer. The anti-reflective layer is formed on the substrate and includes a plurality of diffractive microstructures.