Display devices include waveguides with metasurfaces as in-coupling and/or out-coupling optical elements. The metasurfaces may be formed on a surface of the waveguide and may include a plurality or an array of sub-wavelength-scale (e.g., nanometer-scale) protrusions. Individual protrusions may include horizontal and/or vertical layers of different materials which may have different refractive indices, allowing for enhanced manipulation of light redirecting properties of the metasurface. Some configurations and combinations of materials may advantageously allow for broadband metasurfaces. Manufacturing methods described herein provide for vertical and/or horizontal layers of different materials in a desired configuration or profile.

Disclosed herein are metasurfaces formed on a substrate from a plurality of posts. The metasurfaces are configured to be optically active at one or more wavelengths and in certain embodiments are configured to form lenses having unexpectedly strong focusing power. In particular, the metasurfaces are formed from “low-contrast” materials, including CMOS-compatible materials such as silicon dioxide or silicon nitride. Accordingly, the disclosed metasurfaces are generally CMOS compatible and therefore embody a new paradigm in metasurface design and manufacturing.

A diffraction optical element is disclosed. The diffraction optical element includes a substrate and multiple grating units. The grating units are disposed above the substrate. The grating units diffract incident light to generate diffracted light being passing through the substrate. A refractive index of the substrate is substantially below 1.45.

A window can comprise a first side and a second side substantially parallel to the first side. The window can comprise an optical grating operatively positioned with respect to one of the first side and the second side. The optical grating can be used to determine a temperature at or near the respective one of the first side and the second side.

A diffraction device includes a ZnS member and a ZnSe member coupled to the ZnS member, and a diffraction grating is provided on the ZnSe member.

An optical device includes an overcoat layer on a surface-relief grating. The overcoat layer is formed by a process including: depositing a layer of a first resin material that is curable by heat or electromagnetic radiation on a surface-relief grating that includes a plurality of grating ridges and a plurality of grating grooves to at least partially fill the plurality of grating grooves, curing the layer of the first resin material, depositing a layer of a second resin material that is curable by heat or electromagnetic radiation and has a higher flowability than the first resin material on the layer of the first resin material, annealing the layer of the second resin material to allow the second resin material to flow and form a planar top surface, and curing the layer of the second resin material.

A grating coupler may be fabricated by exposing a photopolymer layer to grating forming light for forming periodic refractive index variations in the photopolymer layer. The photopolymer layer may be exposed to apodization light for reducing an amplitude of the periodic refractive index variations in a spatially-selective manner. The apodization may also be achieved or facilitated by subjecting outer surface(s) of the photopolymer layer to a chemically reactive agent that causes the refractive index contrast to be reduced near the surface(s) of application. The apodized refractive index profile of the gratings facilitates the reduction of optical crosstalk between different gratings of the grating coupler.

In various embodiments, one or more prisms are utilized in a wavelength beam combining laser system to regulate beam size and/or to provide narrower wavelength bandwidth.

The present disclosure is directed to projection devices that can project patterned light of different colors. In one implementation, the projection device can include a housing, within which reside multiple components. These components can include light emitting diodes (LEDs), a parabolic mirror reflector, a sinusoidal lenticular diffuser, and multiple spatial filters. The multiple LEDs can be provided in at least two distinct colors. The parabolic mirror reflector can be arranged to collimate light received from the multiple LEDs. The sinusoidal lenticular diffuser can be positioned at an output of the parabolic mirror reflector and arranged to diffuse the collimated light. The spatial filters can be arranged to diffuse the diffused and collimated light received from the sinusoidal lenticular diffuser. An imaging lens can be coupled to the housing and arranged to magnify the diffused light received from the spatial filters and display a cloud-like effect on a first surface.

Provided are an optical system and an aiming device. The optical system includes a wavefront modulation element with a first surface and a second surface disposed opposite to each other. The first surface of the wavefront modulation element is configured to receive a first light wave without a complete plane wavefront. The second surface of the wavefront modulation element is configured to emit a second light wave with a complete plane wavefront obtained due to the light beam shaping of the first light wave by the wavefront modulation element. The aiming device includes a housing and the optical system.