A telecentric lens comprises a front optical group adapted to receive rays coming from an observed object, a rear optical group, adapted to convey said rays towards an image plane of a sensor, and a lens aperture positioned between the front optical group and the rear lens group, wherein the lens aperture lies on the focal plane at least of the front optical group. The front optical group is devoid of lenses and is consists of a concave curved primary mirror adapted to receive and reflect the rays coming from the observed object, and at least one secondary mirror adapted to receive and reflect towards the rear optical group the rays coming from the primary mirror.

An image pickup apparatus including an optical system and an image pickup element. The optical system includes a first refractive surface disposed closest to an object, a first reflection surface, and a second reflection surface. A light receiving surface of the image pickup element is disposed at only one side with respect to the optical axis and at a position closer to the optical axis than an intersection between a straight line connecting an intersection on the first refractive surface and an intersection on an imaginary extension surface of the second reflection surface and an imaginary extension surface of the light receiving surface. Expression 1.5L2/L16.5 is satisfied where L1 is an interval between the first reflection surface and the second reflection surface, and L2 is an interval between the first reflection surface and the light receiving surface.

Imaging systems and methods are provided for taking high-magnification photographs confined to a small physical volume. In some embodiments the system is composed of at least one lens, one or more partially reflective elements, and a sensor. The partial reflectors reflect a portion of the light back and forth between them to allow a long path length for a portion of the light from the lens to the sensor which enables a high magnification.

A telecentric lens comprises a front optical group adapted to receive rays coming from an observed object, a rear optical group, adapted to convey said rays towards an image plane of a sensor, and a lens aperture positioned between the front optical group and the rear lens group, wherein the lens aperture lies on the focal plane at least of the front optical group. The front optical group is devoid of lenses and is consists of a concave curved primary mirror adapted to receive and reflect the rays coming from the observed object, and at least one secondary mirror adapted to receive and reflect towards the rear optical group the rays coming from the primary mirror.

An optical element includes a refractive material, a plurality of relay curvatures, and dichroic relay mirrors configured as an optical relay. The plurality of relay curvatures is formed in the refractive material. The dichroic relay mirrors include a dichroic reflective layer disposed on the plurality of relay curvatures and immersed in the refractive material. The dichroic reflective layer reflects a first spectrum light and passes light outside the first spectrum light. The first spectrum light may be infrared light.

A head mounted display (HMD) includes a field curvature corrected (FC) display to mitigate field curvature in an image that is output to a user's eyes. The FC display includes elements that generate the image light and elements to mitigate field curvature from the image light. The FC display may include a display panel with lenses, a display panel with a reflective polarizer and reflective surface, or other optical elements. The FC display may include a pancake lens configuration including a polarized display with a quarter wave plate, a reflective mirror, and a polarization reflective mirror.

A projection exposure method for exposing a radiation-sensitive substrate with at least one image of a pattern of a mask is provided in which an illumination field of the mask is illuminated by illumination radiation with an operating wavelength that was provided by an illumination system.

A head mounted display (HMD) includes a field curvature corrected (FC) display to mitigate field curvature in an image that is output to a user's eyes. The FC display includes elements that generate the image light and elements to mitigate field curvature from the image light. The FC display may include a display panel with lenses, a display panel with a reflective polarizer and reflective surface, or other optical elements. The FC display may include a pancake lens configuration including a polarized display with a quarter wave plate, a reflective mirror, and a polarization reflective mirror.

In one aspect of the present disclosure an optical measurement device includes a sample holder defining a sample plane, wherein the sample holder is configured to arrange a sample carrier including an array of measurement positions in the sample plane, an illumination unit configured to illuminate the sample plane, a detector and an optical imaging system configured to image the sample plane including the array of measurement positions onto the detector, the optical imaging system including two or more curved reflective elements adapted to image the sample plane onto the detector with a magnification of between 2:1 and 1:2 and the detector being configured to take an image of all measurement positions of the array of measurement positions at a time.

A lens has a first transmissive surface, a reflective surface, and a second transmissive surface sequentially arranged from a demagnifying side toward a magnifying side. The first transmissive surface and the reflective surface are located at the lower side of an imaginary axis extending in an axis-Z direction, and the second transmissive surface is located at the upper side of the imaginary axis. The reflective surface has a concave shape, and the second transmissive surface has a convex shape protruding toward the magnifying side. An imaginary line that connects an upper intersection to a lower intersection inclines with respect to an imaginary vertical line perpendicular to the imaginary axis in a plane YZ.