Color-selective waveguides, methods for fabricating color-selective waveguides, and augmented reality (AR)/mixed reality (MR) applications including color-selective waveguides are described. The color-selective waveguides can advantageously reduce or block stray light entering a waveguide (e.g., red, green, or blue waveguide), thereby reducing or eliminating back-reflection or back-scattering into the eyepiece.

Diffractive backlight fabrication employs a diffraction grating to scatter light from a light guide and define a reflective island that is aligned with the diffraction grating. A method of fabricating a diffractive backlight includes providing the light guide having the diffraction grating, diffractively scattering guided light out of the light guide using the diffraction grating to selectively expose photoresist and provide an opening in the photoresist, and depositing a reflective material into the opening to form a reflective island that is aligned with the diffraction grating. A reflective diffraction grating element of the diffractive backlight includes the diffraction grating and reflective island.

Fabricating a diffractive backlight employs a universal grating and selects a portion of the universal grating using a reflective island to define a grating element, a reflective diffraction grating element of the diffractive backlight including the grating element and the reflective island. A method of fabricating a diffractive backlight includes forming the universal grating, forming the reflective island, and selecting a portion of the universal grating using the reflective island to define the grating element. The method of fabricating a diffractive backlight may include forming the reflective island on a light guide surface and forming the universal grating over the reflective island. Alternatively, the method of fabricating a diffractive backlight may include forming the universal grating on the light guide surface and forming the reflective island over the universal grating.

A method for manufacturing a concave diffraction grating is provided. The method includes the steps of: positioning a flat mold and a concave substrate such that a pressing surface, having a groove pattern of a diffraction grating, of the flat mold faces a concave surface, coated with a resin, of the concave substrate; pressing the pressing surface against the resin coated over the concave surface by pressurizing the flat mold using a fluid; and curing the resin having the groove pattern transferred thereto by being pressed by the pressing surface. This makes it possible to improve load non-uniformity and manufacture a concave diffraction grating with high surface accuracy.

A plasma etching method using a Faraday cage, which effectively produces a blazed grating pattern.

Techniques disclosed herein relate generally to surface-relief structures. In one embodiment, a surface-relief grating includes a plurality of grating ridges. The plurality of grating ridges includes a first set of grating ridges characterized by a first refractive index, and a second set of grating ridges interleaved with the first set of grating ridges and characterized by a second refractive index different from the first refractive index. The plurality of grating ridges is imprinted in a polymer layer by a nanoimprint lithography process and is exposed to a light pattern to form the first set of grating ridges and the second set of grating ridges that have different refractive indices.

A method for making a housing that defines a cavity for a pressure sensor, the method comprising: providing a bulk of material that will form the housing; focusing a radiation beam on internal portions of the bulk of material so as to modify the internal portions, thereby defining the housing's shape, wherein upstream of the focus of the radiation beam other portions of the bulk material remain unmodified; and discarding either the modified portions or the unmodified portions of the bulk material so as to form the cavity.

An iridescent vehicle badge (and methods for making it) that includes a translucent, polymeric badge having a non-planar shape and comprising an interior and an exterior surface. Further, at least one of the surfaces of the badge comprises a plurality of diffraction gratings that are integral with the badge, each having a thickness from 250 nm to 1000 nm and a varying period from 50 nm to 5 microns. In some cases, the thickness can range from 500 nm to 750 nm. The period, in some cases, can vary within a set of discrete values in one or more portions of the at least one of the surfaces of the badge, e.g., from 150 nm to 400 nm.

The present disclosure relates to display systems and, more particularly, to augmented reality display systems. In one aspect, a method of fabricating an optical element includes providing a substrate having a first refractive index and transparent in the visible spectrum. The method additionally includes forming on the substrate periodically repeating polymer structures. The method further includes exposing the substrate to a metal precursor followed by an oxidizing precursor. Exposing the substrate is performed under a pressure and at a temperature such that an inorganic material comprising the metal of the metal precursor is incorporated into the periodically repeating polymer structures, thereby forming a pattern of periodically repeating optical structures configured to diffract visible light. The optical structures have a second refractive index greater than the first refractive index.

Methods of fabricating optical lenses and mirrors, systems and composite structures based on diffractive waveplates, and fields of application of said lenses and mirrors that include imaging systems, astronomy, displays, polarizers, optical communication and other areas of laser and photonics technology. Diffractive lenses and mirrors of shorter focal length and larger size, with more closely spaced grating lines, and with more exacting tolerances on the optical characteristics, can be fabricated than could be fabricated by previous methods.