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.

In a scanning optical apparatus, an illumination optical system has a diffractive power dM and a refractive power nM in a main scanning direction, and a ratio nM/dM in the main scanning direction for a focal length fi in a range of 10-22 mm satisfies: g2(fi)nM/dMg1(fi), where A(Z)=(1.89710.sup.7)Z.sup.2+6744Z+0.5255, B(Z)=(2.96410.sup.7)Z.sup.2+5645Z+0.6494, C(Z)=(3.27010.sup.7)Z.sup.2+3589Z+0.5250, D(Z)=(5.01610.sup.7)Z.sup.2+4571Z+0.8139, g1(fi)=fi{D(Z)B(Z)}/125D(Z)/6+11B(Z)/6, .[.g2(fi)=fi{C(Z)D(Z)}/125C(Z)/6+11A(Z)/6.]. .Iadd.g2(fi)=fi{C(Z)A(Z)}/125C(Z)/6+11A(Z)/6.Iaddend..

A phase-adjusting element configured to provide substantially liquid-invariant extended depth of field for an associated optical lens. One example of a lens incorporating the phase-adjusting element includes the lens having surface with a modulated relief defining a plurality of regions including a first region and a second region, the first region having a depth relative to the second region, and a plurality of nanostructures formed in the first region. The depth of the first region and a spacing between adjacent nanostructures of the plurality of nanostructures is selected to provide a selected average index of refraction of the first region, and the spacing between adjacent nanostructures of the plurality of nanostructures is sufficiently small that the first region does not substantially diffract visible light.

From an object plane to an image plane along an optical axis, a camera lens including a first lens, a diffractive optical element and a lens module is provided in various embodiments. The first lens has a positive focal power. The diffractive optical element has a positive focal power and a negative dispersion property. A surface that is of the diffractive optical element or the first lens and that faces the object plane side is a convex surface at the optical axis, a surface that is of the diffractive optical element or the first lens and that faces the image plane side is a concave surface at the optical axis. The lens module includes N lenses. At least one of a surface facing the object plane side and a surface facing the image plane side that are of each of the N lenses is an aspheric surface.

An optical assembly includes a Fresnel lens and a diffractive optical element. The Fresnel lens includes a high-refractive-index material having a refractive index greater than 1.9. The diffractive optical element is optically coupled with the Fresnel lens to compensate for chromatic aberration caused by the Fresnel lens. A method for imaging light with the optical assembly is also disclosed.

An optical hybrid lens comprises a substrate having a first surface and a second surface opposite the first surface. A sub-wavelength grating lens is disposed on the first surface and comprises a plurality of posts. The plurality of posts is arranged on the first surface and the posts extend from the first surface. A refractive lens is arranged on the sub-wavelength grating lens at least partly enclosing the plurality of posts. Alternatively, the refractive lens is arranged on the second surface.

The present disclosure provides wavelength discriminating imaging systems and methods that spatially separate (over different depths) the wavelength constituents of an image using a dispersive lens system or element, such that this spectral information may be exploited and used. The wavelength constituents of an image are deconstructed and identified over different depths using a dispersive lens system or element.

Structures for scattering light at multiple wavelengths are disclosed. Scattering elements are fabricated with different geometric dimensions and arrangements, to scatter or focus light at the the same focal distance for each wavelength, or at different focal distances according to the desired application. The scattering elements fabricated on a substrate can be peeled off with a polymer matrix and attached to a lens to modify the optical properties of the lens.

An image display device includes an image light generation unit configured to generate image light, a projection system optical unit configured to project the image light, a correction system optical unit configured to correct aberrations, a first diffraction element configured to deflect the image light incident on a first incident surface, and a second diffraction element configured to deflect the image light incident on a second incident surface. The projection system optical unit, the second diffraction element, the correction system optical unit, and the first diffraction element are arranged in this order in a direction of the image light emitted from the image light generation unit, and the image light deflected and dispersed into rays of respective wavelengths by the second diffraction element is focused by the first diffraction element.

An image pickup optical system of the present invention includes, in order from the object side to the image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, and a third lens unit, and the second lens unit moves during focusing. The first lens unit consists of, in order from the object side to the image side, a first lens sub-unit having a positive refractive power, a second lens sub-unit having a negative refractive power, and a third lens sub-unit having a positive refractive power, and the focal length of the second lens sub-unit and the focal length of the image pickup optical system are appropriately set.