A transmissive optical element may include a substrate. The transmissive optical element may include a first anti-reflectance structure for a particular wavelength range formed on the substrate. The transmissive optical element may include a second anti-reflectance structure for the particular wavelength range formed on the first anti-reflectance structure. The transmissive optical element may include a third anti-reflectance structure for the particular wavelength range formed on the second anti-reflectance structure. The transmissive optical element may include at least one layer disposed between the first anti-reflectance structure and the second anti-reflectance structure or between the second anti-reflectance structure and the third anti-reflectance structure.

A transmissive optical element may include a substrate. The transmissive optical element may include a first anti-reflectance structure for a particular wavelength range formed on the substrate. The transmissive optical element may include a second anti-reflectance structure for the particular wavelength range formed on the first anti-reflectance structure. The transmissive optical element may include a third anti-reflectance structure for the particular wavelength range formed on the second anti-reflectance structure. The transmissive optical element may include at least one layer disposed between the first anti-reflectance structure and the second anti-reflectance structure or between the second anti-reflectance structure and the third anti-reflectance structure.

Diffractive optical elements and methods for their fabrication are disclosed. In one aspect, a diffractive optical element is disclosed, which comprises a polymeric substrate substantially transparent to at least one electromagnetic radiation wavelength, and a plurality of metallic inclusions distributed in said polymeric substrate according to a predefined pattern such that said inclusions can collectively diffract at least a portion of incident radiation having said at least one radiation wavelength.

Diffractive optical elements and methods for their fabrication are disclosed. In one aspect, a diffractive optical element is disclosed, which comprises a polymeric substrate substantially transparent to at least one electromagnetic radiation wavelength, and a plurality of metallic inclusions distributed in said polymeric substrate according to a predefined pattern such that said inclusions can collectively diffract at least a portion of incident radiation having said at least one radiation wavelength.

A switchable grating may be used to redirect illuminating light for illuminating a user’s eye in an eye tracking system, to facilitate the determination of eye position and/or orientation. The eye tracking system may be used in a near-eye display. An eye tracking camera obtains an eye image, and a controller performs an initial determination of the eye position. The controller may switch the switchable grating to direct the illuminating light beam onto the eye, for a better position and/or eye orientation determination.

An input-coupler of an optical waveguide couples light corresponding to the image and having a corresponding FOV into the optical waveguide, and the input-coupler splits the FOV of the image coupled into the optical waveguide into first and second portions by diffracting a portion of the light corresponding to the image in a first direction toward a first intermediate-component, and diffracting a portion of the light corresponding to the image in a second direction toward a second intermediate-component. An output-coupler of the waveguide combines the light corresponding to the first and second portions of the FOV, and couples the light corresponding to the combined first and second portions of the FOV out of the optical waveguide so that the light corresponding to the image and the combined first and second portions of the FOV is output from the optical waveguide. The intermediate-components and the output-coupler also provide for pupil expansion.

An input-coupler of an optical waveguide couples light corresponding to the image and having a corresponding FOV into the optical waveguide, and the input-coupler splits the FOV of the image coupled into the optical waveguide into first and second portions by diffracting a portion of the light corresponding to the image in a first direction toward a first intermediate-component, and diffracting a portion of the light corresponding to the image in a second direction toward a second intermediate-component. An output-coupler of the waveguide combines the light corresponding to the first and second portions of the FOV, and couples the light corresponding to the combined first and second portions of the FOV out of the optical waveguide so that the light corresponding to the image and the combined first and second portions of the FOV is output from the optical waveguide. The intermediate-components and the output-coupler also provide for pupil expansion.

A light diffraction element, that has cells, includes first regions and second regions. Each of the cells comprises one of the first regions and one of the second regions. Each of the first regions has a thickness or a refractive index that is independently set. The second regions have a uniform thickness or a uniform refractive index. The first regions allow first polarized components of signal light to pass through. The second regions allow second polarized components of signal light to pass through. The second polarized components are different, in polarization direction, from the first polarized components. The light diffraction element performs optical computing by causing the first polarized components of signal light that have passed through the first regions to interfere with each other. The first polarized components of signal light output from the light diffraction element indicate information after the optical computing.

An eyepiece for projecting an image to an eye of a viewer includes a first planar waveguide positioned in a first lateral plane, a second planar waveguide positioned in a second lateral plane adjacent the first lateral plane, and a third planar waveguide positioned in a third lateral plane adjacent the second lateral plane. The first planar waveguide includes a first diffractive optical element (DOE) coupled thereto and disposed at a first lateral position. The second planar waveguide includes a second DOE coupled thereto and disposed at a second lateral position. The third planar waveguide includes a third DOE coupled thereto and disposed at the second lateral position. The eyepiece further includes an optical filter positioned between the second planar waveguide and the third planar waveguide at the second lateral position.

An eyepiece for projecting an image to an eye of a viewer includes a first planar waveguide positioned in a first lateral plane, a second planar waveguide positioned in a second lateral plane adjacent the first lateral plane, and a third planar waveguide positioned in a third lateral plane adjacent the second lateral plane. The first planar waveguide includes a first diffractive optical element (DOE) coupled thereto and disposed at a first lateral position. The second planar waveguide includes a second DOE coupled thereto and disposed at a second lateral position. The third planar waveguide includes a third DOE coupled thereto and disposed at the second lateral position. The eyepiece further includes an optical filter positioned between the second planar waveguide and the third planar waveguide at the second lateral position.