A method of fabricating a substrate includes providing a substrate having a flat surface and a beam writing system operable to write in a first direction and a second direction, wherein the second direction is perpendicular to the first direction, The method further includes providing a diffraction grating layout pattern having a first diffraction grating, a second diffraction grating, and a third diffraction grating. The method also includes locating the substrate in the beam writing system, whereby the beam writing system is operable to write into the flat surface, and aligning one of the first, second, and third diffraction gratings parallel with the beam writing system first direction. Additionally, the method includes writing the diffraction grating layout pattern into the substrate flat surface via the beam writing machine.

A monolithic double diffractive kinoform doublet and a method for making such optical element is disclosed. In one embodiment, the optical element includes a first lens and a second lens. The first lens has a first refractive index. The first lens also has a first surface and a second surface. The first surface is a continuous, potentially flat surface for optical radiation to enter. The second lens has a second refractive index different from the first refractive index. The second lens has a first surface and a second surface. The first surface is in contact with the second surface of the first lens. The optical element has a peak diffraction efficiency at a first wavelength and at a second wavelength different than the first wavelength.

An optical device combining a spectacle function with an augmented reality function adapted to let an ambient light beam enter an eye of a user is provided. The optical device includes a spectacle lens and a diffractive optical element. The spectacle lens has a first surface facing the eye and a second surface facing away from the eye. The diffractive optical element is disposed on the first surface of the spectacle lens or between the first surface and the second surface of the spectacle lens. The diffractive optical element has a third surface facing the eye and a fourth surface facing away from the eye. The diffractive optical element is a diffractive optical film or a diffractive optical plate. An augmented reality device is also provided.

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 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.

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.

In an optical display system that includes a waveguide with multiple diffractive optical elements (DOEs), gratings in one or more of the DOEs may have an asymmetric profile in which gratings may be slanted or blazed. Asymmetric gratings in a DOE can provide increased display uniformity in the optical display system by reducing the “banding” resulting from optical interference that is manifested as dark stripes in the display. Banding may be more pronounced when polymeric materials are used in volume production of the DOEs to minimize system weight, but which have less optimal optical properties compared with other materials such as glass. The asymmetric gratings can further enable the optical system to be more tolerant to variations—such as variations in thickness, surface roughness, and grating geometry—that may not be readily controlled during manufacturing particularly since such variations are in the submicron range.

A manufacturing system for fabricating self-aligned grating elements with a variable refractive index includes a patterning system, a deposition system, and an etching system. The manufacturing system performs a lithographic patterning of one or more photoresists to create a stack over a substrate. The manufacturing system performs a conformal deposition of a protective coating on the stack. The manufacturing system performs a deposition of a first photoresist of a first refractive index on the protective coating. The manufacturing system performs a removal of the first photoresist to achieve a threshold value of first thickness. The manufacturing system performs a deposition of a second photoresist of a second refractive index on the first photoresist. The second refractive index is greater than the first refractive index. The manufacturing system performs a removal of the second photoresist to achieve a threshold value of second thickness to form a portion of an optical grating.

A manufacturing system for fabricating self-aligned grating elements with a variable refractive index includes a patterning system, a deposition system, and an etching system. The manufacturing system performs a lithographic patterning of one or more photoresists to create a stack over a substrate. The manufacturing system performs a conformal deposition of a protective coating on the stack. The manufacturing system performs a deposition of a first photoresist of a first refractive index on the protective coating. The manufacturing system performs a removal of the first photoresist to achieve a threshold value of first thickness. The manufacturing system performs a deposition of a second photoresist of a second refractive index on the first photoresist. The second refractive index is greater than the first refractive index. The manufacturing system performs a removal of the second photoresist to achieve a threshold value of second thickness to form a portion of an optical grating.

A pupil replication waveguide for a projector display includes a slab of transparent material for propagating display light in the slab via total internal reflection. A diffraction grating is supported by the slab. The diffraction grating includes a plurality of tapered slanted fringes in a substrate for out-coupling the display light from the slab by diffraction into a blazed diffraction order. A greater portion of the display light is out-coupled into the blazed diffraction order, and a smaller portion of the display light is out-coupled into a non-blazed diffraction order. The tapered fringes result in the duty cycle of the diffraction grating varying along the thickness direction of the diffraction grating, to facilitate suppressing the portion of the display light out-coupled into the non-blazed diffraction order.