An optical device includes a lightguide having a first pair of external surfaces parallel to each other, and at least two sets of facets. Each of the sets including a plurality of partially reflecting facets parallel to each other, and between the first pair of external surfaces. In each of the sets of facets, the respective facets are at an oblique angle relative to the first pair of external surfaces, and at a non-parallel angle relative to another of the sets of facets. The optical device is particularly suited for optical aperture expansion.

A head up display can use a catadioptric collimating system. The head up display includes an image source. The head up display also includes a collimating mirror, and a polarizing beam splitter. The light from the image source enters the beam splitter and is reflected toward the collimating mirror. The light striking the collimating mirror is reflected through the beam splitter toward a combiner. A field lens can include a diffractive surface. A corrector lens can be disposed after the beam splitter.

A diamond-shaped lens system includes: a half diamond-shaped lens including refractive material and having a first surface, a second surface and a third surface for refracting incident light beams from an object having a width of X, from the first surface towards the second surface; a first reflective material positioned at the second surface of the half diamond-shaped lens for reflecting the refracted light beams at a first angle toward the third surface; a second reflective material positioned at the third surface of the half diamond-shaped lens for reflecting the light beams reflected from the first reflective material toward the first surface to exit the first surface at a second angle toward the third surface to form an image of the object with a width Y; and; an apparatus for processing the image of the object to reduce chromatic aberrations.

A hologram image display apparatus includes an illumination optical system that emits an illumination light beam wavefront and a spatial light modulator having a light modulation area that converts the illumination light beam wavefront by diffraction to a display light beam wavefront and displays a virtual image. The spatial light modulator forms the display light beam wavefront by modulating the illumination light beam wavefront so that at least a portion of a regular light ray group configuring the display light beam wavefront is a light ray group with a diffraction angle having an absolute value greater than the first-order diffraction angle by the spatial light modulator, and another portion of the regular light ray group is a light ray group with a diffraction angle having an absolute value of the first-order diffraction angle or less by the spatial light modulator.

An augmented reality or virtual reality display device is disclosed. A first input grating (6; 106; 306; 406; 506) is provided on a waveguide assembly to receive light from a first projector (2; 102; 202; 302; 402; 502) and to couple the light into the at least one waveguide. A second input grating (116; 316; 416; 516) is provided to receive light from a second projector (12; 112; 212; 312; 412; 512) and couple the light into the at least one waveguide. An output diffractive optical element couples light out of the at least one waveguide towards a notional viewing position. The first projector provides light to the first input diffractive optical element in a direction that is at a first angle to a waveguide normal vector, and the second projector is configured to provide light to the second input diffractive optical element in a direction that is at a second angle to the waveguide normal vector. The output diffractive optical element is configured to couple light out of the at least one waveguide in a first range of angles for light from the first projector and in a second range of angles for light from the second projector, wherein the first range of angles and the second range of angles are different but are partially overlapping.

A multi-image display apparatus for augmented reality (AR) or mixed reality (MR) includes a diffractive optical lens element, an image forming device configured to form a first image including a first color image, a second color image, and a third color image, and an optical system configured to transfer the first image and a second image to the diffractive optical lens element, the second image transferred along a path different from a path of the first image. The optical system is configured to offset chromatic aberration of the diffractive optical lens element by providing different optical path lengths for the first color image, the second color image, and the third color image.

A lens for headlamps of vehicles provided with a diffraction grating on a surface, wherein a phase function of the diffraction grating is represented by

[00001]$\left(r\right)=\underset{i=1}{\overset{N}{.Math.}}.Math..Math.{}_{2.Math.i}.Math.r^{2.Math.i}$

where r represents distance from the central axis of the lens, and the relationship

|.sub.2|.Math.(0.3R).sup.2<|.sub.4|.Math.(0.3R).sup.4

is satisfied where R represents effective radius of the lens, and wherein a second derivative of the phase function has at least one extreme value and at least one point of inflection where r is greater than 30% of R, a difference in spherical aberration between the maximum value and the minimum value at any value of r in

0rR

is equal to or less than the longitudinal chromatic aberration for visible light, the diffraction grating is at least partially on the surface where r is greater than 30%, and the relationship

[00002]$1<.Math.\frac{\left(R\right)}{R^2}.Math.<10$

is satisfied.

A Pancharatnam Berry Phase (PBP) liquid crystal structure for adjusting or focusing light of a plurality of color channels emitted by a display of a head-mounted display (HMD) comprises a plurality of PBP active elements. Each PBP active element of the structure is configured to act as a half waveplate for light of a corresponding color channel, such that light of the corresponding color channel is adjusted by a predetermined amount. In addition, each PBP active element acts as a one waveplate for light of the remaining color channels, such that light of the remaining color channels passes through the PBP active element substantially unaffected. As such, the PBP structure is able to adjust incident light of the plurality of color channels uniformly in an apochromatic fashion.

An AR or VR display device. First and third input gratings receive light of a first color from first and second projectors, respectively, coupling the light into a first waveguide. Second and fourth input gratings receive light of a second color from the first and second projectors, respectively, coupling the light into a second waveguide. An output diffractive optical element couples light out of the waveguides towards a viewing position. The first and second projectors provide light to the input diffractive optical elements in directions that are at a first and second angle, respectively, to a waveguide normal vector. The output diffractive optical element couples light out of the waveguides in a first range of angles for light from the first projector and in a second range of angles for light from the second projector, the first range of angles and the second range of angles differing but partially overlapping.

Devices and methods are provided for performing color correction of focal dispersion in high-harmonic lenses. The device comprises a multi-order diffractive engineered surface (MODE) lens comprising a MODE primary lens having height transitions in the front surface that segment it into annular zones and a color corrector comprising a diffractive Fresnel lens (DFL). Polychromatic light passing through the MODE primary lens experiences LCA that is corrected by the color corrector. The color corrector can be configured to correct Type 1 LCA resulting from a combined effect of the DFL and a refractive index change versus wavelength associated with material comprising the device that together produce a change in focus of the polychromatic light, as well as Type 2 LCA resulting from a cyclic variation in focal length versus wavelength caused by the abrupt changes in the height of the front surface of the MODE primary lens at the transitions.