A method of fabricating a blazed diffraction grating comprises providing a master template substrate and imprinting periodically repeating lines on the master template substrate in a plurality of master template regions. The periodically repeating lines in different ones of the master template regions extend in different directions. The method additionally comprises using at least one of the master template regions as a master template to imprint at least one blazed diffraction grating pattern on a grating substrate.

Disclosed is an electronic device. In the electronic device according to the present disclosure, a central axis of a viewing angle based on an eye of a user and the central axis of the viewing angle based on a lens optical axis of a camera match each other. An electronic device according to the present disclosure may be associated with an artificial intelligence module, robot, augmented reality (AR) device, virtual reality (VR) device, and device related to 5G services.

Provided are meta illuminators. The meta illuminators according to embodiments include a first light emitter configured to emit pattern light, and a second light emitter configured to emit non-patterned light, wherein the first and second light emitters forms a single body. The first and second light emitters respectively include meta-surfaces that are different from each other, and the different meta-surfaces may be formed on a single material layer. The first light emitter includes a pattern region that transmits a portion of incident light, and the second light emitter does not include the pattern region. A mask may be arranged between the light source and the transparent substrate.

A diffractive beam expander for use in an augmented-reality display is disclosed. The device can include a optical substrate with a first diffractive optical element having a first diffractive grating disposed on one surface and a second diffractive grating disposed on the opposing surface. Portions of the first and second diffractive gratings overlap to define an in-coupling area configured to receive a beam of incoming light. The first diffractive optical element expands at least part of the received light beam by odd-order diffraction expansion in a first region and a second region and expands at least part of the received light beam by even-order diffraction expansion in a third region. The light components by the first diffractive optical element are then coupled into a second diffractive optical element, which is configured to out-couple at least part of the expanded diffracted light components to exit the substrate by diffraction.

The present technology aims to provide a diffraction element that functions like a transmissive hologram, and more particularly, aims to provide a diffraction element suitable for forming an image projection system. The present technology provides a composite diffraction element that includes a stack structure including a first diffraction element, a second diffraction element, and a third diffraction element in this order. The second diffraction element diffractively reflects light that has passed through the first diffraction element and reached the second diffraction element, toward the first diffraction element. The first diffraction element diffractively reflects the light diffractively reflected by the second diffraction element, toward the third diffraction element. The third diffraction element transmits the light diffractively reflected by the first diffraction element, and diffractively reflects zeroth-order light that has passed through the first diffraction element and the second diffraction element.

A lighting apparatus for vehicles with a number of semiconductor-based light sources and a projection device for generating the specified light distribution with a cut-off line. The projection device features a correction device with at least two lenses. The surface of at least one of the lenses is designed as a diffractive lens surface for achromatization in a visible wavelength range. The two lenses are made from different lens materials. The surfaces of at least two lenses are designed as refractive lens surfaces that have their optical power calculated based on a temperature range and/or expansion coefficient of the lens material of at least two lenses such that adding the optical power of the lenses yields a predefined total optical power of the correction device.

Provided are a light guide element and an image display apparatus capable of suppressing the occurrence of multiple images. The light guide element includes a light guide plate and a first incidence diffraction element, a second incidence diffraction element, a first emission diffraction element, and a second emission diffraction element that are provided on the light guide plate, in which the first and second incidence diffraction elements diffract incident light in different directions to be incident into the light guide plate, the first emission diffraction element emits light that is diffracted by the first incidence diffraction element and propagates in the light guide plate, the second emission diffraction element emits light that is diffracted by the second incidence diffraction element and propagates in the light guide plate, a period of a diffraction structure of the first incidence diffraction element and a period of a diffraction structure of the second incidence diffraction element are different from each other, a period of a diffraction structure of the first emission diffraction element and a period of a diffraction structure of the second emission diffraction element are different from each other, the first and second emission diffraction elements are disposed at a position where the first and second emission diffraction elements overlap each other in a plane direction of a main surface of the light guide plate, and a periodic direction of the diffraction structure of the first emission diffraction element and a periodic direction of the diffraction structure of the second emission diffraction element intersect with each other.

A method for assessing the relative alignment of a first and second diffractive element. The method includes illuminating the first diffractive element to form a first diffraction pattern in the far field and illuminating the second diffractive element to form a second diffraction pattern in the far field. The method further comprises determining a positional and/or rotational relationship between the first diffraction pattern and the second diffraction pattern in the far field.

A frame supports a display apparatus against the head of a viewer. A projector fitted within the frame generates a beam of image-bearing light. A light guide coupled to a forward section of the frame has a waveguide, an in-coupling diffractive optic formed on the waveguide for directing image-bearing light beams into the waveguide, a turning optic formed on the waveguide for expanding the respective image-bearing light beams from the in-coupling diffractive optic in a first dimension, and an out-coupling diffractive optic formed on the waveguide for expanding the respective image-bearing light beams in a second dimension orthogonal to the first dimension and forming a virtual image within a viewer eyebox. A mount supports the light guide in front of the viewer and provides a hinge for angular adjustment of the waveguide with respect to the projector.

An image light guide for conveying a virtual image has a waveguide that conveys image-bearing light, formed as a flat plate having an in-coupling diffractive optic with a first grating vector diffracting an image-bearing light beam into the waveguide and directing diffracted light. An out-coupling diffractive optic is formed as a plurality of overlapping diffraction gratings including a first grating pattern having first grating vector k1 and a second grating pattern having a second grating vector k2 for expanding and ejecting the expanded image bearing beams from the waveguide into an expanded eyebox within which the virtual image can be seen.