Abstract: A method for enabling reading of an optical device that has an array of focusing elements and is configured to provide a synthetic image, comprises arranging (210) of the optical device to obtain a first predetermined shape and controlling (220) of an image plane selector to select an image plane at a first position relative a surface of the optical device. An observable two-dimensional section of the synthetic image taken at the selected image plane is thereby provided. A device for enabling reading of an optical device is also disclosed.

Abstract: Projection optical system for forming an image on a substrate and including an illumination relay lens and a projection lens each of which is a catadioptric system. The projection lens may include two portions in optical communication with one another, the first of which is dioptric and the second of which is catadioptric. In a specific case, the projection optical system satisfies 4 < ? ? I ? ? ? T ? < 30 , where ?I and ?T are magnifications of the first portion and the overall projection lens. Optionally, the projection lens may be structured to additionally satisfy 6 < ? ? II ? ? ? T ? < 20 , where ?II is a magnification of the second portion. A digital scanner including such projection optical system and operating with UV light having a spectral bandwidth on the order of 1 picometer. Method for forming an image with such projection optical system.

Abstract: A projection optical system for use in an image display apparatus having an illumination optical system applying light from a light source, and an image display device receiving the light from the illumination optical system to form a projection image includes a projector lens composed of plural lenses, a first mirror, and a second mirror formed of a concave mirror. The projection optical system is configured to project the projection image onto a projection surface. A projection luminous flux passing through the projector lens to be incident on the first mirror is a luminous flux exhibiting divergence. The projection luminous flux reflected off the second mirror after having reflected off the first mirror is converged once, and the once converged projection luminous flux is projected onto the projection surface. A lens surface of a lens located closest to the first mirror among the lenses of the projector lens is convex.

Abstract: A microendoscope, and a microendoscopy method related to the microendoscope, each include a tube housing, where an end of the tube housing is shaped and finished to facilitate collection of light emitted from a sample when examined using the microendoscope. In addition, a catadioptric lens assembly, an endomicroscope that includes the catadioptric lens assembly and a microendoscopy method for microscopic analysis that uses the endomicroscope are predicated upon a second element and a third element within the catadioptric lens assembly that each has a dichroic coating. The placement of the dichroic coating on the second element and the third element provides for different magnification factors as a function of illumination wavelength when using the microendoscopy method.

Abstract: The invention proposes a short-distance front projection system, that is to say with a wide angle, occupying a small volume and offering a possibility of focusing as well a zoom function. It makes it possible to obtain images with a diagonal greater than 2 meters, the whole of the optical system being at least 50 cm from the plane of the image. This projector is constructed on the basis of three optical elements: an ocular, an afocal lens system and a final group forming an objective intended to form the intermediate image in front of the mirror.

Abstract: A catadioptric projection objective has a first objective part, defining a first part of the optical axis and imaging an object field to form a first real intermediate image. It also has a second, catadioptric objective part forming a second real intermediate image using the radiation from the first objective part. The second objective part has a concave mirror and defines a second part of the optical axis. A third objective part images the second real intermediate image into the image plane and defines a third part of the optical axis. Folding mirrors deflect the radiation from the object plane towards the concave mirror; and deflect the radiation from the concave mirror towards the image plane. The first part of the optical axis defined by the first objective part is laterally offset from and aligned parallel with the third part of the optical axis.

Abstract: A magnification optical system forms an enlarged image of an object. It includes a refractive optical system including a plurality of lens groups; and a mirror train including a curved mirror, arranged in this order from an object side, a first focus structure configured to move the respective lens groups of the refractive optical system by different amounts along a normal line of a conjugate surface on the object side, and a second focus structure configured to move the respective lens groups along the normal line of the conjugate surface on the object side by different amounts from those of the first focus structure.

Abstract: An illumination optical unit for projection lithography illuminates an object field with illumination light. The illumination optical unit has a collector for collecting the emission of a light source for the illumination light. The collector is arranged such that it transfers the illumination light from the light source into an intermediate focus. The illumination optical unit furthermore has a field facet mirror and a pupil facet mirror, each having a plurality of facets. The field facets are imaged into the object field by a transfer optical unit. The illumination optical unit additionally has an individual-mirror array having individual mirrors tiltable in a manner driven individually. The array is arranged upstream of the field facet mirror and downstream of the intermediate focus in an illumination beam path.

Abstract: A catadioptric projection objective for imaging a pattern provided in an object plane of the projection objective onto an image plane of the projection objective has a first, refractive objective part for imaging the pattern provided in the object plane into a first intermediate image; a second objective part including at least one concave mirror for imaging the first Intermediate imaging into a second intermediate image; and a third, refractive objective part for imaging the second intermediate imaging onto the image plane; wherein the projection objective has a maximum lens diameter Dmax, a maximum image field height Y?, and an image side numerical aperture NA; wherein COMP1=Dmax/(Y?·NA2) and wherein the condition COMP1<10 holds.

Abstract: A catadioptric optical system includes a first imaging optical system that includes a catadioptric part that collects a light beam from an object to form an intermediate image of the object, and a second imaging optical system that includes a refractive part that images the intermediate image on an image plane. The first imaging optical system includes a first optical element, a second optical element, and a negative lens in an optical path between the first and second optical elements, and the first and second optical elements are disposed so that reflection parts of the first and second optical element face each other. A power ?n of the negative lens, radii of curvature R1n and R2n of lens surfaces of the negative lens at an object side and an image side, respectively, and a power ?1 of the first imaging optical system are appropriately set.

Abstract: Disclosed is a light emitting apparatus. The light emitting apparatus includes a package body; first and second electrodes; a light emitting device electrically connected to the first and second electrodes and including a first conductive semiconductor layer, a second conductive semiconductor layer, and an active layer between the first and second conductive semiconductor layers; and a lens supported on the package body and at least a part of the lens including a reflective structure. The package body includes a first cavity, one ends of the first and second electrodes are exposed in the first cavity and other ends of the first and second electrodes are exposed at lateral sides of the package body, and a second cavity is formed at a predetermined portion of the first electrode exposed in the first cavity.

Abstract: A lens and reflector unit for optical measurements includes first and second convex surface sections of the lens and reflector unit. Both have their respective central normal lines. A first flat surface section has a normal direction that divides the angle between the central normal lines into equal halves. A third convex surface section has a third central normal line, and the fourth convex surface section has a fourth central normal line. A second flat surface section has a normal direction that divides the angle between the third and fourth central normal lines into to equal halves.

Abstract: A magnification optical system forms an enlarged image of an object. It includes a refractive optical system including a plurality of lens groups; and a mirror train including a curved mirror, arranged in this order from an object side, a first focus structure configured to move the respective lens groups of the refractive optical system by different amounts along a normal line of a conjugate surface on the object side, and a second focus structure configured to move the respective lens groups along the normal line of the conjugate surface on the object side by different amounts from those of the first focus structure.

Abstract: A catadioptric projection objective for imaging a pattern provided in an object plane of the projection objective onto an image plane of the projection objective has a first, refractive objective part for imaging the pattern provided in the object plane into a first intermediate image; a second objective part including at least one concave mirror for imaging the first Intermediate imaging into a second intermediate image; and a third, refractive objective part for imaging the second intermediate imaging onto the image plane; wherein the projection objective has a maximum lens diameter Dmax, a maximum image field height Y?, and an image side numerical aperture NA; wherein COMP1=Dmax/(Y?·NA2) and wherein the condition COMP1<10 holds.

Abstract: An inspection system including a catadioptric objective that facilitates dark-field inspection is provided. The objective includes an outer element furthest from the specimen having an outer element partial reflective surface oriented toward the specimen, an inner element nearest the specimen having a center lens comprising an inner element partial reflective surface oriented away from the specimen, and a central element positioned between the outer lens and the inner lens. At least one of the outer element, inner element, and central element has an aspheric surface. The inner element is spatially configured to facilitate dark-field inspection of the specimen.

Abstract: Catadioptric projection objective (1) for microlithography for imaging an object field (3) in an object plane (5) onto an image field (7) in an image plane (9). The objective includes a first partial objective (11) imaging the object field onto a first real intermediate image (13), a second partial objective (15) imaging the first intermediate image onto a second real intermediate image (17), and a third partial objective (19) imaging the second intermediate image onto the image field. The second partial objective is a catadioptric objective having exactly one concave mirror and having at least one lens (L21, L22). A first folding mirror (23) deflects the radiation from the object plane toward the concave mirror and a second folding mirror (25) deflects the radiation from the concave mirror toward the image plane. At least one surface of a lens (L21, L22) of the second partial objective has an antireflection coating having a reflectivity of less than 0.

Abstract: A telescope, mirror assembly and method of forming an aspheric mirror is disclosed. The telescope includes the mirror assembly which has a substantially spherical surface contour in a relaxed state. A plurality of actuators distributed substantially along an outer edge of the mirror is configured to apply a load to the mirror assembly to deform the mirror to obtain a substantially aspheric surface contour.

Abstract: Various aspects as described herein are directed to apparatuses, methods, and systems including a sandwiched arrangement having a light-access port, a scanning mirror, an optics region, and a spacer. The spacer provides a light-directing optical region that separates the scanning mirror and the optics region, and includes a mirrored surface that reflects light between the light-access port and the optics region. Additionally, the optics region includes a curved-shaped window that provides a field of view by communicating beams of light between a target region. The optics region also includes a curved-shaped mirror having a surface that reflects light between the scanning mirror and the mirrored surface. Light beams, as conveyed between the light-access port and the curved-shaped window, are folded by being reflected off the scanning mirror, the curved-shaped mirror and the mirrored surface.

Abstract: Optical systems and apparatuses configured for enabling substantially simultaneous observation of a plurality of points in an array from a common reference point. Without the optical systems and apparatuses disclosed herein, less than all of the plurality of points can be observed substantially simultaneously from the common reference point.

Abstract: Image-intensifying or night vision glasses are suitable for certain commercial and entertainment applications by virtue of their light weight, small size, and economical production, compared to certain other night vision products. In one embodiment, input light passes through two Amici prisms and a field-flattening lens to reach an image intensifier. The intensified image it produces is reflected off a first folding mirror, passes through a lens, reflects off a curved mirror, and passes back through the lens the other way. The intensified image then passes through two additional, non-doublet lenses, between which an intermediate image exists. The intensified image then reflects off the “lens” or visor of the glasses and proceeds to the pupil of the eye of the wearer. Alternative embodiments use a helmet visor, mirror, or other (at least partially) reflective surface for the final reflection.

Abstract: An imaging system having reduced susceptibility to thermally-induced stress birefringence comprising relay optics and projection optics. One of either the relay optics or the projection optics is a reflective optical system that includes reflective optical elements, and the other is a refractive optical system having a negligible or low susceptibility to thermal stress birefringence. The refractive optical system includes: a first group of refractive lens elements located upstream from an aperture stop, and a second group of refractive lens elements located downstream from the aperture stop. The refractive lens elements in the first and second groups that are immediately adjacent to the aperture stop are fabricated using optical materials having a negligible susceptibility to thermal stress birefringence, and the other refractive lens elements in the first and second groups are fabricated using optical materials having at most a moderate susceptibility to thermal stress birefringence.

Abstract: According to one embodiment, there is provided an imaging element array including an imaging element group in which a plurality of imaging elements are aligned, each of the imaging elements including an integrally molded input portion, an output portion, and a reflective portion, collecting light input to the input portion, reflecting the light by the reflective portion near a position where light flux is downsized, and outputting the reflected light from the output portion to form an image at an image point, and an inhibiting portion which is formed around the reflected portion in the imaging element group to inhibit light other than the light reflected by the reflective portion from traveling to the output portion.

Abstract: A projection system includes: a relay system that focuses light having exited through a first image plane on a second image plane; and an enlarging system that enlarges and projects an image focused on the second image plane on a third image plane, wherein the relay system includes a first lens element on which the light having exited through the first image plane is incident, the first lens element having positive refracting power, a reflective member that reflects a light having passed through the first lens element, the reflective member having positive refracting power, and a second lens element on which a light reflected off the reflective member is incident and which focuses the light reflected off the reflective member on the second image plane, the second lens element having positive refracting power.

Abstract: A continuous zoom lens arrangement can image MWIR and LWIR spectral bands to a common image plane. Such an exemplary optical system comprises eight infrared imaging lenses that all transmit over the wavelengths 3.5-11.0 microns and form a collocated image plane for the MWIR and LWIR spectral bands. The lens has six stationary lenses, and two lenses that move in an axial fashion. A cold stop inside the dewar can act as the aperture stop of the system and control the stray light from reaching the FPA. The pupil is reimaged from the cold stop to near the first lens of the system to minimize the size of the lens.

Abstract: A magnification optical system forms an enlarged image of an object. It includes a refractive optical system including a plurality of lens groups; and a mirror train including a curved mirror, arranged in this order from an object side, a first focus structure configured to move the respective lens groups of the refractive optical system by different amounts along a normal line of a conjugate surface on the object side, and a second focus structure configured to move the respective lens groups along the normal line of the conjugate surface on the object side by different amounts from those of the first focus structure.

Abstract: A projection optical system for projecting an image on a surface is provided. The image is an enlarged image of an image which is formed on an image forming element. The projection optical system includes a coaxial optical system having an optical axis; and a non-coaxial optical system including a rotationally asymmetric curved-surface mirror. The non-coaxial optical system does not share the optical axis with the coaxial optical system. The coaxial optical system includes a first lens having a positive refractive power and being an aspheric plastic lens; and a second lens having a negative refractive power and being an aspheric plastic lens. The first lens has a first refractive index distribution, and the second lens has a second refractive index distribution.

Abstract: A head-mounted display (HMD) that enables a wearer to favorably view and recognize images even in a very bright environment, has a HMD in which image display light emitted from a display element is guided to an eye of an observer via a visor, whereby a virtual image of an observed subject is formed in front of the observer. In the HMD, light source devices are a first light source, outputting light of a high intensity, and a second light source, outputting light of a. low intensity. The light source devices have a switch to switch between the first and second light sources. The display element, the visor and the second light source are attached to a mount, worn on the head of the observer. The first light source is installed in a moveable body with the observer, and is connected to the mount via light transmission paths.

Abstract: Disclosed is an enlargement optical system configured to form an image of an object at an enlargement side, including a lens system and a mirror system in order from a side of the object, the lens system including at least one lens, the mirror system including a first mirror and a second mirror in order from a side of the object, and the second mirror being an concave mirror, wherein an intermediate image conjugate to the object is formed at a side of the object with respect to the second mirror and the first mirror is held to be capable of adjusting a position thereof.

Abstract: The present invention relates to an optical imaging device, in particular for microscopy, with a first optical element group and a second optical element group, wherein the first optical element group and the second optical element group, on an image plane, form an image of an object point of an object plane via at least one imaging ray having an imaging ray path. The first optical element group comprises a first optical element with a reflective first optical surface in the imaging ray path and a second optical element with a reflective second optical surface in the imaging ray path, wherein the first optical surface is concave. The second optical element group comprises a third optical element with a concave reflective third optical surface in the imaging ray path and a fourth optical element with a convex reflective fourth optical surface in the imaging ray path without light passage aperture.

Abstract: A catadioptric projection objective has a first objective part, defining a first part of the optical axis and imaging an object field to form a first real intermediate image. It also has a second, catadioptric objective part forming a second real intermediate image using the radiation from the first objective part. The second objective part has a concave mirror and defines a second part of the optical axis. A third objective part images the second real intermediate image into the image plane and defines a third part of the optical axis. Folding mirrors deflect the radiation from the object plane towards the concave mirror; and deflect the radiation from the concave mirror towards the image plane. The first part of the optical axis defined by the first objective part is laterally offset from and aligned parallel with the third part of the optical axis.

Abstract: New and useful concepts for an imaging optical system configured to simultaneously image a reticle to a pair of imaging locations are provided, where the imaging optics comprise a pair of arms, each of which includes catadioptric imaging optics. In addition, the imaging optics are preferably designed to image a reticle simultaneously to the pair of imaging locations, at a numerical aperture of at least 1.3, and without obscuration of light by the imaging optics.

Abstract: A catadioptric projection objective has a first objective part, defining a first part of the optical axis and imaging an object field to form a first real intermediate image. It also has a second, catadioptric objective part forming a second real intermediate image using the radiation from the first objective part. The second objective part has a concave mirror and defines a second part of the optical axis. A third objective part images the second real intermediate image into the image plane and defines a third part of the optical axis. Folding mirrors deflect the radiation from the object plane towards the concave mirror; and deflect the radiation from the concave mirror towards the image plane. The first part of the optical axis defined by the first objective part is laterally offset from and aligned parallel with the third part of the optical axis.

Abstract: Focus assemblies for laser radar are situated to receive a measurement beam that is focused at or in the focus assemblies. In some examples, focus assemblies include a corner cube and a return reflector, and the measurement beam is focused on, at, or within the corner cube or return reflector. A polarizing beam splitter and a quarter wave plate can be situated so that an input measurement beam and an output measurement beam can be separated.

Abstract: A projection lens configured to form an image from an image source which is disposed at an object side is provided. The projection lens includes a lens group and an aspheric mirror. The lens group has a first optical axis, and an intermediate image is formed by the lens group from the image source. The aspheric mirror has a second optical axis and an aspheric surface. The lens group is disposed between the object side and the aspheric mirror. The aspheric surface faces the lens group and reflects the intermediate image to form the image at an image side. The first optical axis is not coaxial with the second optical axis, and an offset of the image relative to the first optical axis is larger than or equal to 100%.

Abstract: An imaging optical unit for a projection exposure apparatus serves for imaging an object field in an object plane into an image field in an image plane. The image field is arranged at a field distance from the object plane. The optical unit has a plurality of mirrors. The imaging optical unit has a wavefront aberration over the image field of a maximum of 0.3 nm and an image-side numerical aperture of at least 0.5. The image field in at least one dimension has an extent of at least 10 mm. The result is an imaging optical unit in particular suited as part of an optical system for a projection exposure apparatus for projection lithography.

Abstract: A projection optics for microlithography, which images an object field in an object plane into an image field in an image plane, where the projection optics include at least one curved mirror and including at least one refractive subunit, as well as related systems, components, methods and products prepared by such methods, are disclosed.

Abstract: A projection optical system substantially consists of a first optical system composed of a plurality of lenses and a second optical system composed of one reflection mirror having a convex aspherical surface arranged in this order from the reduction side and is configured, when an air space between the first optical system and the second optical system is taken as T12 and a displacement in a direction of the optical axial from a position of maximum effective height on the magnification side lens surface of the lens disposed on the most magnification side in the first optical system to the vertex of the lens surface is taken as Zf, to satisfy a conditional expression (1):0.1<Zf/T12<1.0, in which an image formed on a conjugate plane on the reduction side is magnified and projected onto a conjugate plane on the magnification side.

Abstract: A projection optical system substantially consists of a first optical system composed of a plurality of lens groups and a second optical system composed of one reflection mirror having a convex aspherical surface arranged in this order from the reduction side, in which all optical surfaces constituting the first and second optical systems are formed so as to have rotationally symmetrical shapes around one common axis, the projection optical system is configured such that focus adjustment is performed by individually moving two lens groups in the first optical system along the common axis, and the lens disposed on the most magnification side in the reduction side lens group of the two lens groups is a lens having a convex surface on the magnification side, thereby magnifying and projecting an image formed on a conjugate plane on the reduction side to a conjugate plane on the magnification side.

Abstract: A multi-function, range-Doppler, synthetic aperture and micro-Doppler, coherent laser radar system having improved spatial resolution and immunity to undesired platform motion utilizing two or more simultaneous, spatially offset transceiver apertures.

Abstract: A projection lens includes a first image system, a second image system, and a concave reflector arranged in order. The first image system and the second image system define an optical axis, and the concave reflector is disposed at a first side of the optical axis. A projection apparatus using the projection lens is also provided, wherein the first image system is disposed between a light valve of the projection apparatus and the second image system, and the light valve is disposed at the first side of the optical axis.

Abstract: Provided is a multiple light source microscope which is capable of performing not only electron image observation but also fluorescence image observation, fluoroscopic image observation and the like for the same biological tissue sample, and is provided with a plurality of observation-use light sources. Disclosed is this multiple light source microscope configured by: an optical microscope unit for observing fluorescence, provided with a light source unit; and a scanning electron microscope unit, wherein the optical microscope has a Cassegrain mirror with an aspherical reflecting surface, and the Cassegrain mirror is arranged in a lens barrel of the scanning microscope unit so as to be coaxial with an optical axis of an electron beam of the scanning electron microscope unit.

Abstract: A projection optical system includes first and second optical systems. The first optical system includes a transmissive-refractive element and the second optical system includes a reflective-refractive element. An image formed by a spatial light modulator is projected by the projection optical system on a projection surface. A light beam that travels along an optical path that leads from the second optical system to the projection surface in an optical path between a center of the image formed by the spatial light modulator and the projection surface is projected at an angle with respect to a normal to the projection surface. An optical axis of the first optical system is folded to a folded position by an optical path deflecting unit in an area of the first optical system where the light beam entering the optical path deflecting unit is a converging light beam or a substantially parallel light beam.

Abstract: Provided are a reticle unit that can secure excellent visibility of a reticle regardless of the background and an optical instrument including the reticle unit. A reticle unit 30 used in an optical instrument such as a rifle scope 50 includes: a reflector 32 provided with a concave portion 32b on one of surfaces of a plate-like optical member, wherein at least part of a side surface of the concave portion 32b is a reflection surface 32c; a light source 33 that is arranged laterally to the reflector 32 and that emits light; and a light collector 34 that is arranged between the light source 33 and the reflector 32 and that collects the light from the light source 33 to guide the light to the reflection surface 32c, wherein at least part of the light incident on the reflection surface 32c is totally reflected by the reflection surface 32c and emitted from the other surface of the reflector 32.

Abstract: An automated adaptive optics and laser projection system is described. The automated adaptive optics and laser projection system includes an adaptive optics system and a compact laser projection system with related laser guidance programming used to correct atmospheric distortion induced on light received by a telescope. Control of the automated adaptive optics and laser projection system is designed in a modular manner in order to facilitate replication of the system to be used with a variety of different telescopes. Related methods are also described.

Abstract: Optical devices based on internal conical refraction for developing new set-ups, methods and applications based on the specific properties of internal conical diffraction. The devices include several set-ups, methods and applications consisting of biaxial crystal(s)—one or more polarization elements and optical elements. The biaxial crystal is an optical crystal which may belong to the trigonal, orthorhombic or trigonal crystal classes.

Abstract: An immersion projection optical system having, for example, a catadioptric and off-axis structure, reduces the portion of an image space filled with liquid (immersion liquid). The projection optical system, which projects a reduced image of a first plane onto a second plane through the liquid, includes a refractive optical element (Lp) arranged nearest to the second plane. The refractive optical element includes a light emitting surface (Lpb) shaped to be substantially symmetric with respect to two axial directions (XY-axes) perpendicular to each other on the second plane. The light emitting surface has a central axis (Lpba) that substantially coincides with a central axis (40a) of a circle (40) corresponding to a circumference of a light entering surface (Lpa) of the refractive optical element. The central axis of the light emitting surface is decentered in one of the two axial directions (Y-axis) from an optical axis (AX).

Abstract: Various embodiments provide a Cassegrain-like telescope. The Cassegrain-like telescope includes a primary mirror; a secondary mirror spaced apart from the primary mirror, the primary mirror and the second mirror configured to form a focal surface; and an optical aberrations corrector having a plurality of lenses, the optical aberrations corrector being disposed between the secondary mirror and the focal surface, the optical aberration corrector being configured to correct optical aberrations of the primary mirror and the secondary mirror. A material of the plurality of lenses is selected to transmit radiation in a wavelength range between approximately 0.4 ?m and approximately 12 ?m, and is selected to have variations in refractive index below about 0.05 so as to reduce chromatic aberration to a level such that an average root mean square of wave front error (RMS WFE) is less than approximately 0.08.

Abstract: A projection optical system and a projection display device using the same is provided, wherein the projection optical system has a sufficiently small size to be provided in a front-projection-type projector and can effectively correct various aberrations. An original image on an image display surface is enlarged and projected onto a screen by a first optical system that includes a plurality of lenses and a second optical system that includes a reflecting mirror having a concave surface with an aspheric shape. All of the optical surfaces of the first optical system and the second optical system are rotationally symmetric surfaces each having the optical axis common to all of the optical surfaces as its center. A first lens surface, which is a reduction-side surface, and a second lens surface, which is a magnification-side surface, of a lens (fourteenth lens) closest to a magnification side in the first optical system satisfy predetermined conditional expressions.

Abstract: Catadioptric projection objective (1) for microlithography for imaging an object field (3) in an object plane (5) onto an image field (7) in an image plane (9). The objective includes a first partial objective (11) imaging the object field onto a first real intermediate image (13), a second partial objective (15) imaging the first intermediate image onto a second real intermediate image (17), and a third partial objective (19) imaging the second intermediate image onto the image field. The second partial objective is a catadioptric objective having exactly one concave mirror and having at least one lens (L21, L22). A first folding mirror (23) deflects the radiation from the object plane toward the concave mirror and a second folding mirror (25) deflects the radiation from the concave mirror toward the image plane. At least one surface of a lens (L21, L22) of the second partial objective has an antireflection coating having a reflectivity of less than 0.

Abstract: An imaging system having reduced susceptibility to thermally-induced stress birefringence comprising relay optics and projection optics. One of either the relay optics or the projection optics is a reflective optical system that includes reflective optical elements, and the other is a refractive optical system having a negligible or low susceptibility to thermal stress birefringence. The refractive optical system includes: a first group of refractive lens elements located upstream from an aperture stop, and a second group of refractive lens elements located downstream from the aperture stop. The refractive lens elements in the first and second groups that are immediately adjacent to the aperture stop are fabricated using optical materials having a negligible susceptibility to thermal stress birefringence, and the other refractive lens elements in the first and second groups are fabricated using optical materials having at most a moderate susceptibility to thermal stress birefringence.