A diffractive optical element includes a plurality of diffractive layers. The plurality of diffractive layers includes adjacent diffractive layers including a plurality of optical axes that change along in-plane rotation directions opposite to

Disclosed is an improved diffraction structure for 3D display systems. The improved diffraction structure includes an intermediate layer that resides between a waveguide substrate and a top grating surface. The top grating surface comprises a first material that corresponds to a first refractive index value, the underlayer comprises a second material that corresponds to a second refractive index value, and the substrate comprises a third material that corresponds to a third refractive index value. According to additional embodiments, improved approaches are provided to implement deposition of imprint materials onto a substrate, which allow for very precise distribution and deposition of different imprint patterns onto any number of substrate surfaces.

The cost and power consumption of an imaging apparatus are reduced by facilitating detection of an incident angle of a light beam transmitted through a grating substrate. An image sensor converts an optical image captured by pixels arranged on an imaging surface and outputs the converted image signal. A modulator is configured to modulate intensity of light; and an image processing circuit performs image processing of the output image signal. The modulator has a grating substrate, a grating pattern formed on a back surface side of the grating substrate arranged in proximity to the light receiving surface of the image sensor; and a grating pattern formed on a front surface facing the back surface. Each of the grating patterns is constituted of a plurality of concentric circles. The modulator performs intensity modulation on the light transmitted through the grating pattern and outputs the modulated light to the image sensor.

An optical waveguide comprises at least two TIR surface and contains a grating. Input TIR light with a first angular range along a first propagation direction undergoes at least two diffractions at the grating. Each diffraction directs light into a unique TIR angular range along a second propagation direction.

A design method of a diffractive optical assembly, and a diffractive optical assembly are provided. The design method comprises: designing a first diffractive optical element according to a target light field; simulating the first diffractive optical element to obtain a first light field difference between the simulation light field of the first diffractive optical element and the target light field; and designing a second diffractive optical element according to the first light field difference.

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm.

An optical element includes a first birefringent medium layer with orientations of directors of first optically anisotropic molecules spatially varying with a first in-plane pitch and a first vertical pitch. The optical element also includes a second birefringent medium layer with orientations of directors of second optically anisotropic molecules spatially varying with a second in-plane pitch and a second vertical pitch. The second birefringent medium layer is optically coupled with the first birefringent medium layer and configured to reduce a diffraction of a light by the first birefringent medium layer. The first in-plane pitch is substantially the same as the second in-plane pitch, and the second vertical pitch is smaller than the first vertical pitch.

An optical element includes a first birefringent medium layer with orientations of directors of first optically anisotropic molecules spatially varying with a first in-plane pitch and a first vertical pitch. The optical element also includes a second birefringent medium layer with orientations of directors of second optically anisotropic molecules spatially varying with a second in-plane pitch and a second vertical pitch. The second birefringent medium layer is optically coupled with the first birefringent medium layer and configured to reduce a diffraction of a light by the first birefringent medium layer. The first in-plane pitch is substantially the same as the second in-plane pitch, and the second vertical pitch is smaller than the first vertical pitch.

Disclosed is an improved diffraction structure for 3D display systems. The improved diffraction structure includes an intermediate layer that resides between a waveguide substrate and a top grating surface. The top grating surface comprises a first material that corresponds to a first refractive index value, the underlayer comprises a second material that corresponds to a second refractive index value, and the substrate comprises a third material that corresponds to a third refractive index value. According to additional embodiments, improved approaches are provided to implement deposition of imprint materials onto a substrate, which allow for very precise distribution and deposition of different imprint patterns onto any number of substrate surfaces.

A near eye display (NED) includes an electronic display configured to output image light. Further, the NED includes an eye tracking module and multiple optical elements that are combined to form an optical system to allow for changes in position of one or both eyes of a user of the NED. Various types of such optical elements, which may have optical states that are switchable, may be used to steer a light beam toward the user's eye. A direction of the steering may be based on eye tracking information measured by the eye tracking module.