A system is provided. The system includes a light source configured to emit an infrared light to illuminate an eye of a user. The system includes a grating disposed facing the eye and including a birefringent material film configured with a uniform birefringence lower than or equal to 0.1. The grating is configured to diffract the infrared light reflected from the eye, and transmit a visible light from a real world environment toward the eye, with a diffraction efficiency less than a predetermined threshold. The system includes an optical sensor configured to receive the diffracted infrared light and generate an image of the eye based on the diffracted infrared light.

An optical assembly includes a partial reflector that is optically coupled with a first polarization volume holographic element. The partial reflector is capable of receiving first light having a first circular polarization and transmitting a portion of the first light having a first circular polarization. The first polarization volume holographic element is configured to receive the first portion of the first light and reflect the first portion of the first light as second light having the first circular polarization. The partial reflector is capable of receiving the second light and reflecting a first portion of the second light as third light having a second circular polarization opposite to the first polarization. The first polarization volume holographic element is configured to receive the third light having the second circular polarization and transmit the third light having the second circular polarization.

A system is provided. The system includes a light source configured to emit an infrared light to illuminate an eye of a user. The system includes a grating disposed facing the eye and including a birefringent material film configured with a uniform birefringence lower than or equal to 0.1. The grating is configured to diffract the infrared light reflected from the eye, and transmit a visible light from a real world environment toward the eye, with a diffraction efficiency less than a predetermined threshold. The system includes an optical sensor configured to receive the diffracted infrared light and generate an image of the eye based on the diffracted infrared light.

An optical system includes a substrate and a polarization volume hologram (PVH) composite film formed over the substrate. The PVH composite film includes a first PVH layer formed over the substrate and having a helix twist of a first handedness, and a second PVH layer coupled to the first PVH layer and having a helix twist of a second handedness orthogonal to the first handedness. The first PVH layer is configured to reflect and converge circularly polarized light having the first handedness. The second PVH layer is configured to reflect and converge circularly polarized light having the second handedness.

A lens includes a substrate with optically anisotropic molecules arranged in helical configurations between first and second surfaces. A first portion of the substrate includes a first helical structure having a first phase and a second helical structure adjacent to the first helical structure having a second phase. A difference between the first and second phases corresponds to a first phase difference. A second portion includes a third helical structure having a third phase and a fourth helical structure adjacent to the third helical structure having a fourth phase. A difference between the third and fourth phases corresponds to a second phase difference. A third portion includes a fifth helical structure having a fifth phase and a sixth helical structure adjacent to the fifth helical structure having a sixth phase. A difference between the fifth and sixth phases corresponds to a third phase difference.

A polarization volume hologram (PVH) lens includes a PVH layer having a freeform design. The PVH layer includes a first region and a second region having different optical properties.

An optical assembly includes a partial reflector that is optically coupled with a first polarization volume holographic element. The partial reflector is capable of receiving first light having a first circular polarization and transmitting a portion of the first light having a first circular polarization. The first polarization volume holographic element is configured to receive the first portion of the first light and reflect the first portion of the first light as second light having the first circular polarization. The partial reflector is capable of receiving the second light and reflecting a first portion of the second light as third light having a second circular polarization opposite to the first polarization. The first polarization volume holographic element is configured to receive the third light having the second circular polarization and transmit the third light having the second circular polarization.

Disclosed are various methods for creating optical elements through holographic fabrication. One method includes positioning a reflector in an optical path, disposing a first substrate proximal to the reflector along the optical path, disposing a first photosensitive film on the side of the first substrate facing the reflector, transmitting a light beam at a first polarization from a light source along the optical path, reflecting the light beam off the reflector, wherein the reflected light beam has a second polarization, receiving the reflected light beam through the first film and the first substrate, and applying a liquid crystal layer to the first photosensitive film to reproduce the alignment pattern of the first film on the liquid crystal layer.

An optical master is created by using a nanoimprint alignment layer to pattern a liquid crystal layer. The nanoimprint alignment layer and the liquid crystal layer constitute the optical master. The optical master is positioned above a photo-alignment layer. The optical master is illuminated and light propagating through the nanoimprinted alignment layer and the liquid crystal layer is diffracted and subsequently strikes the photo-alignment layer. The incident diffracted light causes the pattern in the liquid crystal layer to be transferred to the photo-alignment layer. A second liquid crystal layer is deposited onto the patterned photo-alignment layer, which subsequently is used to align the molecules of the second liquid crystal layer. The second liquid crystal layer in the patterned photo-alignment layer may be utilized as a replica optical master, or as a diffractive optical element for directing light in optical devices such as augmented reality display devices.

An optical device includes an optical component (e.g., a polarization volume hologram, a geometric phase device, or a polarization-insensitive diffractive optical element) having a uniform thickness and configured to modify a wavefront of a light beam that includes light in two or more wavelengths visible to human eyes, where the optical component has a chromatic aberration between the two or more wavelengths. The optical device also includes a metasurface on the optical component. The metasurface includes a plurality of nanostructures configured to modify respective phases of incident light at a plurality of regions of the metasurface, where the plurality of nanostructures is configured to, at each region of the plurality of regions, add a respective phase delay for each of the two or more wavelengths to correct the chromatic aberration between the two or more wavelengths.