Abstract: The present disclosure relates to a light source apparatus, a microscopic device, an optical detection device, and an optical detection method. The light source apparatus comprises: an illumination light source configured to generate illumination light; and a diaphragm disposed on an emergent light path of the illumination light source, comprising: a light shielding screen configured to block part of the illumination light; a first light-transmitting portion provided on the light shielding screen and covering a center of the diaphragm, the first light-transmitting portion being configured to make part of the illumination light transmit therethrough to form bright-field illumination; and a second light-transmitting portion provided on the light shielding screen and located at a periphery of the first light-transmitting portion, the second light-transmitting portion being configured to make part of the illumination light transmit therethrough to form dark-field illumination.

Abstract: An optical apparatus, which illuminates a first area with light from a light source while the first area is longer in a second direction intersecting a first direction than in the first direction, includes a collector optical member which is arranged in an optical path between the light source and the first area, and condenses the light from the light source to form a second area in a predetermined plane, the second area being longer in a fourth direction intersecting a third direction than in the third direction; and a first fly's eye optical member which is provided within the predetermined plane including the second area, and has a plurality of first optical elements guiding the light of the collector optical member to the first area.

Abstract: A small, handheld Raman spectrometer device can be built from a laser, lenses, and a diffraction grating configured in a right-angle Raman spectroscopy geometry, and used in conjunction with a cell-phone camera to record the Raman spectra. The cell-phone-based Raman spectrometer system is suited to performing in-situ measurements of chemical and biological molecules.

Abstract: An image-reading apparatus includes: a light-receiving unit that receives reflected light from a recording material on which an image is formed; and multiple light-reflecting members that reflect the reflected light from the recording material toward the light-receiving unit. At least one light-reflecting member of the multiple light-reflecting members reflect the reflected light multiple times.

Abstract: A near-eye optical system is configured to receive an image beam. The near-eye optical system includes a first optical waveguide, configured to expand the image beam in a first direction, and including a first surface, a second surface, a plurality of first reflecting slopes, and a plurality of second reflecting slopes. The first surface includes a first light-entering area. The second surface is opposite to the first surface. The second surface includes a concave area aligned with the first light-entering area, the concave area including a flat bottom surface, and a first inclined sidewall and a second inclined sidewall opposite to each other. The first reflecting slopes are disposed on the second surface, and the second reflecting slopes are disposed on the second surface.

Abstract: A freeform surface off-axial three-mirror imaging system is provided. The freeform surface off-axial three-mirror imaging system comprises a primary mirror, a secondary mirror, and a compensating mirror. The primary mirror, the secondary mirror, and the compensating mirror are located adjacent and spaced away from each other. A surface shape of each of the primary mirror and the secondary mirror is a quadric surface. The primary mirror is used as an aperture stop. A surface shape of the compensating mirror is a freeform surface. A light emitted from a light source is reflected by the primary mirror, the secondary mirror, and the compensating mirror to form an image on an image plane.

Abstract: An optical device includes: a lens including a first reflector; a display device at a first side surface of the lens and including a plurality of subpixels; and a lens array between the lens and the display device and including a plurality of lenses configured to condense light from the subpixels onto the first reflector.

Abstract: A process is provided for imaging a surface of a specimen with an imaging system that employs a BD objective having a darkfield channel and a bright field channel, the BD objective having a circumference. The specimen is obliquely illuminated through the darkfield channel with a first arced illuminating light that obliquely illuminates the specimen through a first arc of the circumference. The first arced illuminating light reflecting off of the surface of the specimen is recorded as a first image of the specimen from the first arced illuminating light reflecting off the surface of the specimen, and a processor generates a 3D topography of the specimen by processing the first image through a topographical imaging technique. Imaging apparatus is also provided as are further process steps for other embodiments.

Abstract: The present invention relates to a freeform surface reflective infrared imaging system comprising a primary mirror, a secondary mirror, a tertiary mirror, and an infrared light detector. Each reflective surface of the primary mirror, the secondary mirror, and the tertiary mirror is an xy polynomial freeform surface. A field of view of the freeform surface reflective infrared imaging system is larger than or equal to 40°×30°. An F-number of the freeform surface reflective infrared imaging system is less than or equal to 1.39.

Abstract: A spectacle lens for an imaging optical unit for producing a virtual image of an output image presented on an image generator includes an inner surface facing the eye and an outer surface facing away from the eye, an input coupling section, and an output coupling structure. The imaging beam path is guided to the output coupling structure by way of reflections between the inner surface and the outer surface. A reflection surface having a concave curvature when seen from the interior of the spectacle lens is present between the input coupling section and the output coupling structure in the region of the inner surface and/or in the region of the outer surface. The curvature of said reflection surface differs from a basic curvature of the inner surface or of the outer surface of the spectacle lens.

Abstract: A cloaking device includes an object-side, an image-side, an object-side curved cloaking region (CR) boundary having an outward facing mirror surface and an inward facing surface, and an image-side curved CR boundary an outward facing mirror surface and an inward facing surface. A cloaked region is bounded by the inward facing surfaces of the object-side curved CR boundary and the image-side curved CR boundary. At least one exterior boundary with an inward facing mirror surface is spaced apart from the object-side curved CR boundary and the image-side curved CR boundary. Light from an object positioned on the object-side of the cloaking device and obscured by the cloaked region is redirected around the cloaked region to form an image of the object on the image-side of the cloaking device such that the light from the object appears to pass through the CR.

Abstract: A cloaking device assembly comprises an object-side, an image-side, a reference optical axis extending from the object-side to the image-side, a cloaked region positioned between the object-side and the image-side and a cloaked article positioned within the cloaked region. An object-side converging lens is positioned on the object-side, an image-side converging lens is positioned on the image-side, and a hexagonal prism is positioned within the cloaked region between the object-side converging lens and the image-side converging lens. Light from an object positioned on the object-side of the cloaking device and obscured by the cloaked region propagates through the object-side converging lens, the hexagonal prism, and the image-side converging lens to form an image of the object on the image-side of the cloaking device such that the cloaked region and the cloaked article within the cloaked region do not appear to be positioned between the object and the image.

Abstract: An eye tracking system includes a light guide comprising a first eye-facing surface, a second surface, a third surface, and a plurality of facets formed in the second surface. The facets reflect a portion of light incident on a user eye into the light guide, which is positioned proximate to the user eye and between the user eye and a display. A surface of a compensator may be shaped complementary to the second surface of the light guide and placed proximate to the light guide. A camera or image sensor is oriented toward the third surface of the light guide and captures an image based on internally reflected light. An IR light source may be included. The image sensor may be an IR image sensor. Based on the image, a pose of the user eye is determined. A faceted light guide assembly may include a reflective coating adjacent the facets.

Abstract: A cloaking device includes an object-side, an image-side, and a cloaked region (CR) between the object-side and the image-side. An object-side CR reflection boundary, an object-side half-mirror, and an object-side external reflection boundary are positioned on the object-side, and an image-side CR reflection boundary, an image-side half-mirror, and an image-side external reflection boundary are positioned on the image-side. The object-side half-mirror and the object-side external reflection boundary are spaced apart and generally parallel to the object-side CR reflection boundary, and the image-side half-mirror and the image-side external reflection boundary are spaced apart and generally parallel to the image-side CR reflection boundary. Light from an object located on the object-side of the cloaking device and obscured by the CR is redirected around the CR via two optical paths to form an image of the object on the image-side of the cloaking device.

Abstract: A cloaking device includes an object-side, an image-side, a cloaked region (CR) between the object-side and the image-side, and a reference optical axis extending from the object-side to the image-side. An object-side CR reflection boundary and an object-side optical component sub-assembly are positioned on the object-side and an image-side CR reflection boundary and an image-side optical component sub-assembly are positioned on the image-side. The object-side optical component sub-assembly includes an object-side outward-positioned half-mirror, an object-side inward-positioned half-mirror, and at least one of an object-side outward-positioned reflection boundary and an object-side half-wave plate. The image-side optical component sub-assembly includes an image-side outward-positioned half-mirror, an image-side inward-positioned half-mirror, and at least one of an image-side outward-positioned reflection boundary and an image-side half-wave plate.

Abstract: A cloaking device includes a prism and a light guide. The prism is attachable to an article and is configured for directing around the article a light ray reflected from an object that is blocked from view. The prism has an object surface and an article surface spaced opposite the object surface. The guide is disposed on solely the object surface and has a refraction surface at least partially spaced apart from the object surface. The guide is configured for directing the ray through the prism such that the object is not blocked from view. The refraction surface and the ray define a first angle therebetween of less than 90°. The guide is formed from a first transparent material having a first refractive index and the prism is formed from a second transparent material having a second refractive index that is greater than or equal to the first refractive index.

Abstract: A light guide for a virtual image device to guide and emit image light output from an image display element to display a virtual image. The light guide includes a light-guide member and an optical member. The light-guide member includes an incidence portion to receive the image light and an exit portion to emit the image light to an outside, and a reflective portion inclined relative to the incidence portion to guide the image light received by the incidence portion into the light guide. The light-guide member also includes an extraction portion including first planes each inclined relative to the exit portion and second planes each parallel with the exit portion, to guide the image light from each first plane to the exit portion and extract the image light. The optical member includes a parallel plane and an inclined portion.

Abstract: Various light-scanning systems that can be used to perform rapid point-by-point illumination of a focal plane within a specimen are disclosed. The light-scanning systems can be incorporated in confocal microscopy instruments to create an excitation beam pivot axis that lies within an aperture at the back plate of an objective lens. The light-scanning systems receive a beam of excitation light from a light source and direct the excitation beam to pass through the pivot point in the aperture of the back plate of the objective lens while continuously scanning the focused excitation beam across a focal plane.

Abstract: An optical cloaking system which optically cloaks/hides an object in the visible light spectrum such that the object appears invisible, while permitting a background behind the object to be viewed substantially without distortion. The system includes at least one optical device manufactured using common optical materials in the form of prisms, lenses, mirrors, and the like, which is placed between an observer an the object to be cloaked, and the optical device bends and/or compresses light such that the light passes around a cloaked space in which an object is disposed, and the observer viewing a larger space including the cloaked space will not see the object, but will see a background behind the object in full view substantially undistorted in relation to the rest of the larger space.

Abstract: A light collector includes a light guide having a refractive index larger than a refractive index of air and a reflecting surface configured to reflect light output from a conic surface of the light guide back to the light guide. The light guide is made of transparent material through which light passes. The light guide has an entering portion from which light enters and an exiting portion from which the light exits. The light guide has a circular cone shape and has a cross-sectional area that decreases in a direction from the entering portion to the exiting portion.

Abstract: The disclosure generally relates to imaging optical systems that include a plurality of mirrors, which image an object field lying in an object plane in an image field lying in an image plane, where at least one of the mirrors has a through-hole for imaging light to pass through. The disclosure also generally relates to projection exposure installations that include such imaging optical systems, methods of using such projection exposure installations, and components made by such methods.

Abstract: A magnifying imaging optical system is disclosed that has precisely three mirrors, which image an object field in an object plane into an image field in an image plane. A ratio between a transverse dimension of the image field and a transverse dimension measured in the same direction of a useful face of the last mirror before the image field is greater than 3. In a further aspect, the magnifying imaging optical system is disclosed that has at least three mirrors, which image an object field in an object plane in an image field in an image plane. A first mirror in the beam path after the object field is concave, a second mirror is also concave and a third mirror is convex. An angle of incidence of imaging beams on the last mirror before the image field is less than 15°.

Abstract: An all-reflective afocal lens is comprised of eight-reflective mirrors which can fold the light path into a very compact and thin configuration while maintaining diffraction limited performance. Such an afocal arrangement is usable with a traditional optical imager of an appropriate aperture dimension and FOV range, or with an annular aperture optical system with the appropriately scaled aperture and acceptable FOV angles. When combined the resulting FOV is scaled by the magnification produced by the afocal. The afocal arrangement can be used in either a magnification mode or a demagnification mode. Such an afocal arrangement can be used as either a focal length extender or as a FOV switch enabling a very short length two FOV multi-spectral system with a length that can be an order of magnitude shorter than a known optical system.

Abstract: An apparatus includes a first plurality of concave reflecting surfaces; a second plurality of reflecting surfaces facing the first plurality of concave reflecting surfaces such that a region is defined between the first and second pluralities; and an input for an optical beam to enter the region and an output for the optical beam to exit the region. The first and second pluralities of reflecting surfaces are arranged relative to each other so that the optical beam is re-imaged at a reflecting surface of one of the pluralities after only one reflection from a reflecting surface of the other of the pluralities and so that overlap of two or more optical beams on each of the reflecting surfaces is avoided.

Abstract: A coude gimbal structure includes a two-axis gimbal system having an outer gimbal pivotable about a first rotational axis, and an inner gimbal supported on the outer gimbal and pivotable about a second rotational axis which intersects the first rotational axis at an intersection point. A folded afocal three-mirror anastigmat has a positive-optical-power primary mirror, a negative-optical-power secondary mirror, and a positive-optical-power tertiary mirror, and a first flat fold mirror, and a second flat fold mirror. A beam path incident upon the primary mirror is reflected from the primary mirror to the secondary mirror. The tertiary mirror lies on the second rotational axis, the first flat fold mirror redirects the beam path reflected from the secondary mirror to the tertiary mirror, and the second flat fold mirror lies at the intersection point and redirects the beam path reflected from the tertiary mirror along the first rotational axis.

Abstract: The image displaying apparatus includes an image production apparatus, a first light conduction section and a second light conduction section. The first light conduction section includes a first light conduction plate which propagates part of incident light thereto by total reflection in the inside thereof and emits the propagated light, and a reflection type volume hologram diffraction grating disposed on the first light conduction plate. The second light conduction section includes a second light conduction plate, a first deflection section and a second deflection section.

Abstract: A reflective optical form that has both a telecentric image and a real entrance pupil. In one example, a non-relayed optical imaging system includes a real entrance pupil configured to admit a beam of electromagnetic radiation, an image plane, and a reflective triplet including a negative primary mirror, a positive secondary mirror optically coupled to the primary mirror, a negative tertiary mirror optically coupled to the secondary mirror, the reflective triplet configured to receive the beam of electromagnetic radiation from the real entrance pupil and to focus the beam of electromagnetic radiation onto the image plane to form a telecentric image at the image plane.

Abstract: An imaging optical system has a plurality of mirrors, which via a beam path for imaging light, image an object field in an object plane into an image field in an image plane. The imaging optical system has an exit pupil obscuration. At least one of the mirrors has no opening for passage of the imaging light. The fourth to last mirror in the beam path is concave, resulting in an imaging optical system having improved imaging properties without compromise in throughput.

Abstract: Since a distance from an image extraction part to a light exiting surface is shorter downstream in an optical path than upstream in the optical path in relation to Z direction that is an arraying direction of reflection units, image light that propagates to pass between the image extraction part and the light exiting surface without becoming incident on the reflection units and therefore cannot be extracted to outside can be reduced. That is, since image light having a large total reflection angle in a light guide plate can be securely made incident on the image extraction part and efficiently extracted from the light exiting surface, light use efficiency in image formation can be enhanced. Thus, a virtual image display apparatus with brightness and high performance can be provided.

Abstract: A semiconductor measuring tool has a folding mirror configuration that directs a light beam to pass the same space multiple times to reduce the size and footprint. Furthermore, the folding mirrors may reflect the light beam at less than forty-five degrees; thereby allowing for smaller folding mirrors as compared to the prior art.

Abstract: In general, in one aspect, the invention features an objective arranged to image radiation from an object plane to an image plane, including a plurality of elements arranged to direct the radiation from the object plane to the image plane, wherein the objective has an image side numerical aperture of more than 0.55 and a maximum image side field dimension of more than 1 mm, and the objective is a catoptric objective.

Abstract: According to one embodiment, the imaging device array in an embodiment has plural imaging devices formed integrally, imaging the light that is output from the exit surface imaged at the image point including an incidence surface for the incidence of light, plural reflective surfaces including four reflective surfaces for reflecting the light from the incidence surface, and an exit surface that outputs light that has gone through the plural reflective surfaces, in which the plural imaging devices are arranged as an array, and a surface for ameliorating the propagation of light other than the light reflected from the reflective surfaces to the exit surface is formed on the periphery of at least one reflective surface among the plural reflective surfaces.

Abstract: An all-reflective afocal lens is comprised of eight-reflective mirrors which can fold the light path into a very compact and thin configuration while maintaining diffraction limited performance. Such an afocal arrangement is usable with a traditional optical imager of an appropriate aperture dimension and FOV range, or with an annular aperture optical system with the appropriately scaled aperture and acceptable FOV angles. When combined the resulting FOV is scaled by the magnification produced by the afocal. The afocal arrangement can be used in either a magnification mode or a demagnification mode. Such an afocal arrangement can be used as either a focal length extender or as a FOV switch enabling a very short length two FOV multi-spectral system with a length that can be an order of magnitude shorter than a known optical system.

Abstract: An afocal beam relay has first and second primary concave reflective surfaces and first and second secondary convex toroidal reflective surfaces. The centers of curvature of each of the first and second primary reflective surfaces and first and second secondary reflective surfaces lie on an axis. The first and second secondary convex reflective surfaces face toward the first and second primary concave reflective surfaces and are disposed to relay a decentered entrance pupil to a decentered exit pupil. An aspheric corrector element is disposed in the path of an input beam of light that is directed by the primary and secondary surfaces to the decentered entrance pupil. The directed beam of light between the first and second secondary convex mirrors is collimated in one direction and focused in mid air in an orthogonal direction.

Abstract: There is disclosed a focussing system for concentrating radiation onto a target surface, comprising: a first reflective element forming part of the surface of a cone axially aligned along a first alignment axis, the first reflective element being positioned such that when planar radiation is incident on the first reflective element in a direction parallel to the first alignment axis, the planar radiation is focussed towards a first focus lying along the first alignment axis, wherein said part of the surface of a cone is contained within a sector having an included angle of less than 180 degrees; and a second reflective element having a reflective surface that at all points is flat in a direction parallel to a single reference direction, the second reflective element being positioned between the first reflective element and the first focus such that, when planar radiation is incident on the first reflective element in a direction parallel to the first alignment axis, radiation reflected from the first reflecti

Abstract: An imaging optical system includes three reflecting mirrors having first to third reflection surfaces and is configured, such that in an XYZ orthogonal coordinate system using an optical axis at the center of the field of view as Z-axis, the optical axis at the center of the field of view and an optical axis of an image plane are in parallel to each other Assuming that along the path of the beam traveling along the optical axis at the center of the field of view a distance between the second reflection surface and the third reflection surface is L2, a distance between the third reflection surface and the image plane is L3 and fy1 and an equivalent F-number of the imaging optical system is represented as Fno, the relational expression 0.5<Fno(L2/L3)<1.3 is satisfied.

Abstract: This invention relates to a solar photon filter, hereafter known as the SPF, which is a combination band-pass filtering system consisting of a multiple set of cold or hot mirrors and infra-red absorbers set in a 360-degree or linear arrangement. The system removes almost all of the photons carried by waves having lengths longer than 1000 nm (nanometers)+/?100 nm, while passing almost all of the incoming photons carried by waves having lengths shorter than 1000 nm+/?100 nm and/or variations thereof. This is accomplished by positioning a set of cold or hot mirrors in constant optical track with the sun. Such an assembly of cold or hot mirrors allows solar photons carried by light to be split into two distinct bands of frequencies for use requiring such filtering separation.

Abstract: An image display device includes an image generating device, a light guide unit which includes a light guide plate and first and second deflection sections, and a light beam extension device which extends light incident from the image generating device, along a Z direction when an incident direction of light incident on the light guide plate is set to be an X direction and a direction of propagation of light in the light guide plate is set to be a Y direction, and emits the light to the light guide unit, wherein the light beam extension device includes a first reflecting mirror on which light from the image generating device is incident, and a second reflecting mirror which emits light incident from the first reflecting mirror to the light guide unit, and each of the first and second reflecting mirrors has a light reflecting surface having a sawtooth-shaped cross-sectional shape.

Abstract: The present invention discloses a polarization-maintaining reflector arrangement comprising a reflector group including at least one polarizing reflector and at least one compensating reflector, wherein the incident plane for the polarizing reflectors is perpendicular to the incident plane for the compensating reflectors, and the product of s-wave reflectance of all the polarizing reflectors and p-wave reflectance of all the compensating reflectors is equal to the product of s-wave reflectance of all the compensating reflectors and p-wave reflectance of all the polarizing reflectors. One or more reflector groups can be used in the light path. The invention can conveniently and effectively eliminate the polarization caused by reflection.

Abstract: In general, in one aspect, the invention features an objective arranged to image radiation from an object plane to an image plane, including a plurality of elements arranged to direct the radiation from the object plane to the image plane, wherein the objective has an image side numerical aperture of more than 0.55 and a maximum image side field dimension of more than 1 mm, and the objective is a catoptric objective.

Abstract: An all-reflecting, non-relayed optical system having an aperture stop and an optical axis and configured to provide images of objects. The system includes a positive power primary mirror configured to receive radiation from the objects, a negative power secondary mirror configured to receive the radiation reflected from the primary mirror and a positive power tertiary mirror configured to receive the radiation reflected from the secondary mirror. The system further includes a focal plane configured to receive the radiation reflected from the tertiary mirror and to form an image of the objects. The aperture stop of the optical system is located between the tertiary mirror and the image plane. Accordingly, the image plane may be cold shielded to prevent or reduce radiation reflected from the optical elements that interferes with the desired image.

Abstract: An optical device is provided for projecting a light beam. The device comprises a first planar reflector movable about a first axis is disposed in a path of a focused light beam for deflecting the incident light beam; a concave reflective surface fixed in position located in the path of the deflected light beam, has a circular shape extending along at least one of its axis and is spaced apart from the planar reflector by a distance which is approximately equal to the radius of that circular shape; and a second planar reflector moveable about a second axis located in a plane substantially vertical to a plane comprising the first axis and wherein the second planar reflector is positioned in the path of the light reflected by the concave reflective surface such that the light beam is projected onto a target plane with a substantially flat field of focus.

Abstract: An apparatus includes a first plurality of concave reflecting surfaces; a second plurality of reflecting surfaces facing the first plurality of concave reflecting surfaces such that a region is defined between the first and second pluralities; and an input for an optical beam to enter the region and an output for the optical beam to exit the region. The first and second pluralities of reflecting surfaces are arranged relative to each other so that the optical beam is re-imaged at a reflecting surface of one of the pluralities after only one reflection from a reflecting surface of the other of the pluralities and so that overlap of two or more optical beams on each of the reflecting surfaces is avoided.

Abstract: The optical device projects a three dimensional image into free space. A series of minors are aligned thereby allowing an image reflect three times between the two minors. The distance between the mirrors may be altered, changing the size and orientation of the final image. In other arrangements, the minors are aligned to permit an image to reflect five times. The minors of the device are concave, may be spherical or parabolic, and may be fragments of a spherical or parabolic minor.

Abstract: An optical system has a plurality of elements arranged to image radiation at a wavelength ? from an object surface to an image surface, the elements include mirror elements having a reflective surface positioned at a path of radiation. At least one of the mirror elements is a pupil mirror having a pupil mirror surface arranged at or near to a pupil surface of the optical system. At least one of the remaining mirror elements is a highly loaded mirror having a mirror surface arranged at a position where at least one of a largest value of a range of angles of incidence and a largest value of an average angle incidence of all remaining mirrors occurs, where the remaining mirrors include all mirrors except for the pupil mirror.

Abstract: A magnifying imaging optical system is disclosed that has precisely three mirrors, which image an object field in an object plane into an image field in an image plane. A ratio between a transverse dimension of the image field and a transverse dimension measured in the same direction of a useful face of the last mirror before the image field is greater than 3. In a further aspect, the magnifying imaging optical system is disclosed that has at least three mirrors, which image an object field in an object plane in an image field in an image plane. A first mirror in the beam path after the object field is concave, a second mirror is also concave and a third mirror is convex. An angle of incidence of imaging beams on the last mirror before the image field is less than 15°.

Abstract: The disclosure provides an illumination optical system for microlithography that is designed so that, even with a change of illumination setting (e.g., a change in the given illumination conditions in the object field), variation of illumination parameters over the object field is confined within predetermined tolerances.

Abstract: Imaging optics includes a first mirror in the imaging beam path after the object field, a last mirror in the imaging beam path before the image field, and a fourth to last mirror in the imaging beam path before the image field. In an unfolded imaging beam path between the object plane and the image plane, an impingement point of the chief ray on a used region of each of the plurality of mirrors has a mirror spacing from the image plane. The mirror spacing of the first mirror is greater than the mirror spacing of the last mirror. The mirror spacing of the fourth to last mirror is greater than the mirror spacing of the first mirror. Chief rays that emanate from points of the object field that are spaced apart from another have a mutually diverging beam course, giving a negative back focus of the entrance pupil.

Abstract: An imaging optical system has a plurality of mirrors which image an object field in an object plane in an image field in an image plane. The imaging optical system has a pupil obscuration. The last mirror in the beam path of the imaging light between the object field and the image field has a through-opening for the passage of the imaging light. A penultimate mirror of the imaging optical system in the beam path of the imaging light between the object field and the image field has no through-opening for the passage of the imaging light. The result is an imaging optical system that provides a combination of small imaging errors, manageable production and a good throughput for the imaging light.

Abstract: An reflective imaging optical system of the far pupil type, which is applicable to an exposure apparatus using for example the EUV light, forms on a second plane an image of a predetermined area on a first plane and is provided with first to eighth reflecting mirrors arranged in an order of reflection from the first plane toward the second plane. An entrance pupil of reflective imaging optical system is positioned on a side opposite to the reflective imaging optical system with the first plane intervening therebetween; and the following condition is fulfilled provided that PD represents a distance along an optical axis between the entrance pupil and the first plane, TT represents a distance along the optical axis between the first plane and the second plane, and R represents an angle of incidence of a main light beam coming into the first plane: ?14.3<(PD/TT)/R<?2.5.