A lens unit (120) shows longitudinal chromatic aberration and focuses an imaged scene into a first image for the infrared range in a first focal plane and into a second image for the visible range in a second focal plane. An optical element (150) manipulates the modulation transfer function assigned to the first and second images to extend the depth of field. An image processing unit (200) may amplify a modulation transfer function contrast in the first and second images. A focal shift between the focal planes may be compensated for. While in conventional approaches for RGBIR sensors contemporaneously providing both a conventional and an infrared image of the same scene the infrared image is severely out of focus, the present approach provides extended depth of field imaging to rectify the problem of out-of-focus blur for infrared radiation. An imaging system can be realized without any apochromatic lens.

Improved fluoresced imaging (FI) endoscope devices and systems are provided to enhance use of endoscopes with FI and visible light capabilities. An endoscope device is provided for endoscopy imaging in a white light and a fluoresced light mode. A relay system includes an opposing pair of rod lens assemblies positioned symmetrically with respect to a central airspace. The rod lens assemblies include a meniscus lens positioned immediately adjacent to a central airspace and with the convex surface facing the airspace, a first lens having positive power with a convex face positioned adjacent to the inner face of the meniscus lens, a rod lens adjacent to the first lens having positive power and an outer optical manipulating structure selected from various designs providing chromatic aberration correction.

A segmented optical component comprises a multi-order diffractive engineered surface (MODE) lens that is a high-performance ultralightweight optical element that is well suited for use as an efficient large aperture space telescope and other applications. The MODE lens also has the added benefit of reducing the range of focal dispersion versus wavelength, or lateral chromatic dispersion, and off-axis aberration, or zonal field shift (ZFS). The MODE lens can be combined with a DFL. The MODE lens comprises a curved front surface having an M-order diffractive pattern formed therein that segments the MODE lens into Np zones, each comprising a respective zone lens, where Np is greater than or equal to two. Each zone lens operates geometrically as a separate optical element and is separated from an adjacent zone by a transition having a step height.

Provided are a curable resin composition including a near-ultraviolet light-absorbing organic compound, indium tin oxide particles, and a polymer having a constitutional unit represented by General Formula (P) and having an acidic group at one terminal, in which the near-ultraviolet light-absorbing organic compound is a compound that has a maximal value at 300 to 400 nm in an absorption spectrum in a wavelength region of 300 to 800 nm and does not substantially absorb light at a wavelength of 410 to 800 nm; a cured product formed of the curable resin composition; a diffractive optical element; and a multilayer diffractive optical element.

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Ar.sup.P represents an aryl group and L.sup.P and R.sup.P1 represent a specific group.

An optical lens arrangement comprises a first Fresnel lens element and a second lens element. The first Fresnel lens element defines a flat surface side and an opposite faceted surface side defining wedge and draft faces. The flat surface side faces towards the eye of a user and the opposite faceted surface side faces away from the eye of the user. The second lens element interfaces with the faceted surface side of first Fresnel lens. The second lens element is selected from the group consisting of: a second Fresnel lens element, a singlet lens element, a doublet lens element and any combination thereof. The first Fresnel lens is proximal relative to the eye of the user and the second lens element is distal relative to the eye of the user. Head mounted devices (HMD) including these optical lens arrangements are provided. Methods of making such optical lens arrangements and HMDs are also provided.

A diffractive optical element comprises a substrate, a first resin layer arranged on the substrate and a second resin layer arranged on the first resin layer. Each of the first resin layer and the second resin layer includes a grating section, or a layer portion, for forming a diffraction grating and a base section, or another layer portion, held in contact with the grating section. Either the first resin layer or the second resin layer has a lower transmittance portion in the base section thereof that shows an internal transmittance relative to a wavelength of 400 nm which is lower than that of the grating section of the resin layer by not less than 2% and not more than 6%.

The imaging lens consists of, in order from the object side, a front group, an aperture stop, and a rear group. The front group includes a diffractive optical element having a positive lens and a negative lens in order from the object side. A diffractive surface is provided between an object side surface of the positive lens and an image side surface of the negative lens. Assuming that a distance on an optical axis from the diffractive surface to the aperture stop in a state in which an object at infinity is in focus is Ddoe, and a focal length of the whole system in a state in which the object at infinity is in focus is f, the imaging lens satisfies Conditional Expression (1): 0.02<Ddoe/f<0.11.

To overcome the problem of a diffractive surface having a large, and often excessively large, amount of chromatic aberration, an optical system can use multiple cascaded or sequential diffractive surfaces that, combined, have a reduced amount of chromatic aberration. The optical system can be designed such that all rays traversing the optical system and passing through the diffractive surfaces have an equal optical path length. In the design process, the sets of rays are identified, and the designs of the diffractive surfaces are selected to produce the angular deviations to produce the identified ray paths. In one example, an achromatic lens formed as two annular optical surfaces can receive a collimated incident beam, redirect rays helically at the first surface toward the second surface, and redirect the rays at the second surface toward a focal point. The azimuthal redirection can decrease with increasing distance away from a central axis.

A display module includes an image light generation device configured to generate image light, a first diffraction element including a first surface and a second surface and configured to diffract the image light, a first reflection section configured to reflect the image light, and a second diffraction element including a third surface and configured to diffract the image light. The first diffraction element is configured to transmit the image light incident on the first surface and emit the image light toward the first reflection section, the first reflection section is configured to reflect the image light toward the second surface, the first diffraction element is configured to diffract the image light incident on the second surface and emit the image light toward the second diffraction element, and the second diffraction element is configured to diffract the image light, emit the image light, and form an exit pupil.

Improved fluoresced imaging (FI) endoscope devices and systems are provided to enhance use of endoscopes with FI and visible light capabilities. An endoscope device is provided for endoscopy imaging in a white light and a fluoresced light mode. A relay system includes an opposing pair of rod lens assemblies positioned symmetrically with respect to a central airspace. The rod lens assemblies include a meniscus lens positioned immediately adjacent to a central airspace and with the convex surface facing the airspace, a first lens having positive power with a convex face positioned adjacent to the inner face of the meniscus lens, a rod lens adjacent to the first lens having positive power and an outer optical manipulating structure selected from various designs providing chromatic aberration correction.