An imaging lens includes, from an object side to an image side: a first positive lens having a convex object-side surface; an aperture stop; a second negative lens as a meniscus double-sided aspheric lens having a concave object-side surface; and a third positive lens as a meniscus double-sided aspheric lens having a concave image-side surface, wherein the second lens has a diffractive optical surface on the object side, the aspheric object-side and image-side surfaces of the third lens have pole-change points off an optical axis, and conditional expressions (1) to (4) below are satisfied:
8.0<fdoe/f<26.0(1)
20<vd1vd2<40(2)
20<vd3vd2<40(3)
0.8<ih/f<0.95(4).

Methods and systems for correcting chromatic aberrations in a telescope incorporating a diffractive primary optical element are provided. In particular, a corrective optic assembly that includes a corrector diffractive optical element (DOE) is described. The corrective optic assembly provides light to the corrector DOE at a high incidence angle. Moreover, light is reflected from the corrector DOE at a high exit angle comprising a cylindrical Littrow configuration allowing for greater bandwidth and smaller size.

The invention relates to a fixed focal length objective having a stationary lens group forward in the direction of light (VG), a stationary diaphragm (BL) with an adjustable aperture, a stationary rear lens group (HG) and a focussing group (MG) displaceable relative to the diaphragm along the optical axis of the objective for imaging objects at different distances onto a stationary image plane (IM), in which lens the focussing group (MG) consists of at least one lens element and a diffractive optical element (DOE) integrated into the focussing group (MG).

A diffractive optical element and a camera are disclosed. The diffractive optical element may be arranged at a camera head of a camera for assisting the camera in imaging. The diffractive optical element may be configured by inverse design. The diffractive optical element is inversely designed to minimize stray spots during image capture and to enhance its light transmission capability. The inverse design is applied to reduce an etching depth of a patterned region in the diffractive optical element, thereby lowering primary and secondary diffraction efficiency, increasing light transmission capacity, and minimizing stray spots in captured images. The inverse design is further applied to narrow the patterned region in the diffractive optical element, thereby lowering diffraction efficiency and increasing light intake through a light transmissive region, which enables a camera aperture to obtain more light, enhancing background light intake, shutter response speed, and overall quality in imaged background.

The disclosed system may include a display; a lens; and a diffractive optical element, where the diffractive optical element includes at least one Pancharatnam-Berry phase grating and is configured to increase a fill factor of the display when the lens is used to magnify the display. Various other apparatuses, systems, and methods are also disclosed.

A curved waveguide-based augmented reality device is provided. The device includes a projector, and a curved waveguide. The waveguide has a shape of a concentric cylindrical meniscus and includes an in-coupling diffractive optical element and an out-coupling diffractive optical element, a grating period of a diffraction grating of the in-coupling diffractive optical element at each point of the in-coupling diffractive optical element is such that rays from one point of an initial image are input into the curved waveguide in each point of the in-coupling diffractive optical element at the same angle relative to a normal to a surface of the curved waveguide at a point of ray incidence, and at least at one point on each of the diffractive optical elements a diffraction grating period of the in-coupling diffractive optical element is equal to a diffraction grating period of the out-coupling diffractive optical element.