Abstract: An optical system configured to guide a light beam from a display element includes a positive lens, a negative lens, and an optical element having at least three optical surfaces. The light beam from the display element is reflected a plurality of times inside the optical element via the positive lens and the negative lens, and then travels to an exit pupil. A predetermined condition is satisfied.

Abstract: Aspects of the present invention relate to methods and systems for the see-through computer display systems with an extended field of view.

Abstract: An omnidirectional image and video capturing system including a tube, a plurality of reflectors, openings for rays of light to the enter tube, and a stitching, display or decoding non-transitory storage media. The reflectors may include a first mirror, a second mirror, a third mirror, and a fourth mirror and may be angled at an approximate 45-degree angle and a fifth mirror that may capture reflected images from the first (4) four mirrors.

Abstract: A relay optical system 20 for a rigid endoscope includes a lens fixing frame 21 and a plurality of lenses 22. The lens fixing frame 21 has a plurality of tubular bodies 26. The plurality of tubular bodies 26 are joined coaxially to each other. The plurality of lenses 22 are located at positions other than a joint position jp of the tubular bodies 26 in an axis direction of the lens fixing frame 21. The plurality of lenses 22 are located in the lens fixing frame 21 so as to have a coincident optical axis. The plurality of lenses 22 do not include a cemented lens.

Abstract: An apparatus includes a reflecting element with first, second and third reflecting surfaces, and a receiving element configured to receive a light flux from a light source reflected by the reflecting element. A value of an inner product of a unit normal vector of the first reflecting surface and a unit normal vector of the second reflecting surface, a value of an inner product of the unit normal vector of the first reflecting surface and a unit normal vector of the third reflecting surface, and a value of an inner product of the unit normal vector of the second reflecting surface and the unit normal vector of the third reflecting surface are appropriately set.

Abstract: A projection lens system that projects an image of a reduction side into a magnification side includes a diaphragm, a plurality of positive lenses, and a plurality of negative lenses. The plurality of positive lenses include a first positive lens closer to the magnification side than the diaphragm is and closest to the diaphragm, a second positive lens second closest to the diaphragm after the first positive lens on the magnification side, a third positive lens closer to the reduction side than the diaphragm is and closest to the diaphragm. The plurality of negative lenses include a first negative lens closer to the magnification side than the diaphragm is and closest to the diaphragm, and a second negative lens closer to the reduction side than the diaphragm is and closest to the diaphragm. The lenses have transmittances larger than threshold values, respectively.

Abstract: A projection optical system that enlarges and projects an image displayed on an image display includes: a first optical system; and a second optical system. The projection optical system is a monofocal lens or a zoom lens. The first optical system and the second optical system are arranged, in order starting with the first optical system, from an enlargement side of the projection optical system. The second optical system forms an intermediate image of the image between the first optical system and the second optical system. The first optical system enlarges and projects the intermediate image. The first optical system includes: a first-A optical system and a first-B optical system in order from the enlargement side; and a reflecting optical element that bends a light path between the first-A optical system and the first-B optical system.

Abstract: A virtual image display apparatus includes a display device (image forming unit), a first mirror member configured to reflect imaging light from the display device, a second mirror member configured to reflect imaging light reflected by the first mirror member, and a third mirror member of a transmissive type configured to reflect imaging light reflected by the second mirror member toward a position of an exit pupil. One of the first mirror member and the second mirror member is a refractive reflective optical member that includes a refractive member including a refractive surface, and a mirror surface formed at a non-refractive surface of the refractive member.

Abstract: Fixed-element, digital-optical measuring devices are disclosed, as are methods for using these devices. The measuring devices have two separate optical pathways with fixed elements that produce a stereo image. The optical pathways may include mirrors, prisms, beam splitters, and other such elements, or two digital sensors may be used. Image distance between stereo copies of a point of interest in the stereo image is measured digitally and converted to a physical distance from the measuring device. The conversion may be done with a non-trigonometric function, such as a function created using empirical data. In some cases, the function may be a function-of-functions that provides a calibration for a number of different lens focal lengths.

Abstract: The imaging optical system consists of first and second optical systems in order from a magnified side. The second optical system forms an image on an image display surface as an intermediate image. The first optical system forms the intermediate image on a magnified-side conjugate plane. A height H of a principal ray of light having a maximum angle of view becomes maximum on a lens surface of the whole system (having focal length f) on the most magnified side, among heights of principal rays of light having a maximum angle of view on respective lens surfaces, satisfying predetermined Conditional Expressions (1) and (2): 0.03<H×|f|/(L×I)<0.09??(1) 0.35<I/dl??(2) Where L is an optical axis distance between lens surfaces on the most magnified and reduced sides, I is a reduced side maximum image height, and dl is a maximum air spacing on the optical axis within the system.

Abstract: The imaging optical system consists of, in order from a magnification side: a first optical system which makes a magnification side imaging surface and an intermediate image conjugate to each other; and a second optical system which makes the intermediate image and a reduction side imaging surface conjugate to each other. The imaging optical system is configured to be telecentric on the reduction side. The first optical system includes an aspheric lens. The second optical system consists of a front group and a rear group. The imaging optical system satisfies predetermined conditional expressions for a focal length of the front group, a focal length of the imaging optical system, a focal length of the rear group, a maximum image height, a focal length of the first optical system, and the aspheric lens of the first optical system.

Abstract: The imaging optical system consists of, in order from a magnification side, a first optical system and a second optical system. The first optical system consists of, in order from the magnification side, a first A lens group having a positive refractive power and a first B lens group having a positive refractive power with the maximum air gap interposed between the lens surfaces in the first optical system. The second optical system consists of, in order from the magnification side, a second A lens group having a positive refractive power and a second B lens group having a positive refractive power with the maximum air gap interposed between the lens surfaces in the second optical system.

Abstract: The imaging optical system consists of, in order from the magnification side, a first optical system forming an intermediate image and a second optical system re-forming the intermediate image, and is configured to be telecentric on the reduction side. The imaging optical system satisfies predetermined conditional expressions relating to a ray height on a lens surface closest to the magnification side in the second optical system, a ray height on a lens surface closest to the reduction side in the first optical system, and heights of rays at a position where a principal ray with the maximum angle of view intersects with the optical axis in the second optical system.

Abstract: A projection optical system that enlarges and projects an image displayed on an image display includes: a first optical system; and a second optical system. The projection optical system is a monofocal lens or a zoom lens. The first optical system and the second optical system are arranged, in order starting with the first optical system, from an enlargement side of the projection optical system. The second optical system forms an intermediate image of the image between the first optical system and the second optical system. The first optical system enlarges and projects the intermediate image. The first optical system includes: a first-A optical system and a first-B optical system in order from the enlargement side; and a reflecting optical element that bends a light path between the first-A optical system and the first-B optical system.

Abstract: The wide-angle lens consists of a projection lens which is disposed closer to a magnified side than an intermediate image, and a relay lens which is disposed closer to a reduced side than the intermediate image and is configured to be attachable and detachable to and from the projection lens, and satisfies the following Conditional Expressions (1) and (2) 0<|FC/FC2|<0.2??(1) 0.

Abstract: An optical system for an endoscope includes an objective and a reversal system arranged after the objective. The reversal system includes at least one reversal stage for projecting the distal intermediate image as a proximal intermediate image into a proximal intermediate image plane. The reversal system imprints on the proximal intermediate image a first longitudinal chromatic aberration referred to a predetermined wavelength from the visible spectrum and a predetermined wavelength from the near infrared range. The objective imprints on the distal intermediate image a second longitudinal chromatic aberration referred to the predetermined wavelength from the visible spectrum and the predetermined wavelength from the near infrared range. The second longitudinal chromatic aberration has the opposite sign relative to the first longitudinal chromatic aberration, which reduces the longitudinal chromatic aberration caused by the reversal system in the proximal intermediate image.

Abstract: An endoscopic device includes an optical guide head connfigured to be at least partially inserted into a body or a cavity in order to view or image an object or a site that is poorly accessible to the naked eye. The optical guide head of such an endoscopic device is formed from an optical rod with a refractive index gradient.

Abstract: Provided is a sensor head capable of reduction in size while securing measurement accuracy. A sensor head includes a first case section and a second case section each having a substantially cylindrical shape and an end portion of which is open, and a third case section configured to connect the first case section and the second case section, a diffraction lens is disposed in the first case section, an objective lens is disposed in the second case section, and a mirror member is disposed in the third case section and configured to bend light entering the diffraction lens side toward the objective lens side.

Abstract: A device and a method for imaging a sample arranged in an object plane. The device includes an optical relay system that images an area of the sample from the object plane into an intermediate image plane. The device may also include an optical imaging system with an objective having an optical axis that lies perpendicularly on the intermediate image plan, and which is focused on the intermediate image plane, with the result that the object plane can be imaged undistorted onto a detector. The device also can include an illumination apparatus for illuminating the sample with a light sheet, wherein the light sheet lies essentially in the object plane and defines an illumination direction, and wherein the normal of the object plane defines a detection direction.

Abstract: An optical phase-shifting component is used for shifting the phase and modifying the intensity of the light beam injected into the fiber (MMF2). The component is inserted upstream or downstream of, or at an intermediate position in, the fiber. The component uses two mirrors and multiple beam paths between the mirrors. An optical phase-shifting structure (e.g., a reflective phase mask with a structured surface, which can be a mirror) is effective at each reflection of the beam and gradually splits the beam into faster and slower propagation modes. The faster modes are subjected to one or more reflections more than the slower modes and are thereby decelerated. The fast and slow modes are combined again and are then transmitted in a multimode fiber in which the modes have different propagation speeds. The difference in the propagation speeds is thus at least partly compensated.

Abstract: A housing for accommodating optical and electronic components of a video camera of a medical video endoscope. The housing including: a first housing part, a second housing part, the housing parts assembled together to form inner chambers for mounting the optical and electronic components and an axial passage for optically connecting the inner chambers; a window disposed in an end opening in the assembled housing parts, electrical connectors disposed in a wall in the assembled housing parts, wherein, in an unassembled configuration, the inner chambers are accessible from a surface substantially transversely to a longitudinal axis of the housing parts, and the first and second housing parts are configured to mate with each other in such a way that the inner chambers are hermetically sealed from an exterior of the assembled first and second housing parts.

Abstract: This invention relates to a main optical system for an endoscope, in particular, to a main optical system for an endoscope that is focally imaging in the visible and near-infrared lights, which belongs to the technical field of minimally invasive surgery. The used approach is: the objective lens set has a positive off-focus and positive field curvature. The steering set has the negative off-focus and negative field curvature. Moreover, a field lens set is added between the objective lens set and the steering set. The field lens set is located near the focus of the objective lens set. After the field lens is combined with the objective lens set, it will have the positive off-focus and positive field curvature that match to the steering set so that the 850 m defocus amount is less than 0.05 mm and the edge field curvature is less than 0.1 mm in the main endoscope optical system. The system is good in imaging.

Abstract: A relay optics includes a positive first lens group, a positive second lens group, and a positive third lens group. The second lens group includes, closest to the object, a lens having the concave surface facing toward the object. The relay optics is configured in such a manner that a light flux passing between the second and third lens groups is a substantially-parallel light flux, and satisfies condition expressions below, where f1 represents the focal length of the first lens group, d1 represents the length from the primary image to a surface closest to the object in the first lens group, f12 represents the combined focal length of the first and second lens groups, and exp12 represents the length from an exit pupil position of an optics consisting of the first and second lens groups to a surface closest to the object in the second lens group: 1?f1/d1?4.3 0.16?exp12/f12?1.2.

Abstract: A zoom image-forming optical system used in combination with an infinity-correction objective lens, the zoom image-forming optical system including: a tube lens for condensing a luminous flux from the objective lens to form an intermediate image; and a relay lens with a zoom function for projecting the intermediate image onto an image plane. The relay lens includes a first lens group with positive power, a second lens group that belongs to a movable group with positive power, a third lens group that belongs to a movable group with positive or negative power, and a fourth lens group with negative power, in this order from the intermediate image side. The zoom image-forming optical system changes its magnifying power by moving the second lens group and the third lens group in an optical axis direction.

Abstract: Example embodiments of a large dynamic range sequential wavefront sensor for vision correction or assessment procedures are disclosed. An example embodiment includes first and second optically coupled 4F relays and a variable focus lens disposed substantially at the image plane of the first 4F relay and the object plane of the second 4F relay.

Abstract: An eyepiece includes a focusing apparatus for positioning the area perceived as in focus by the relaxed human eye and for correcting axial ametropia of an eye of a user of the eyepiece and a correction apparatus for adjustable correction of an astigmatism of an eye of a user of the eyepiece.

Abstract: The imaging optical system makes magnification conjugate side and reduction conjugate side predetermined positions conjugate to each other and forms an intermediate image conjugate to both the predetermined positions. The optical system includes a magnification side positive lens as a first lens disposed on the magnification conjugate side further than an intermediate imaging position, a reduction side positive lens as a third lens disposed on the reduction conjugate side further than the intermediate imaging position, and a negative lens as a second lens disposed between these positive lenses. Conditions of 5<?2??1<80, 5<?2??3<80, 0.03<N1?N2<1.0 and 0.03<N3?N2<1.0 are satisfied where ?1, ?2 and ?3 represent Abbe numbers of materials of the first, second and third lenses, N1, N2 and N3 represent refractive indices of the materials of the first, second and third lenses.

Abstract: Observation over a superwide field of view is possible with a short, lightweight, and inexpensive eyepiece optical system and a binocular barrel. A microscope optical system includes an objective optical system configured to collect light from a specimen; an imaging optical system configured to image the light coming from the specimen and collected by the objective optical system; and an eyepiece optical system configured to magnify the image of the specimen formed by the imaging optical system and form a virtual image in an eye of an observer, wherein the following conditional expressions are satisfied, M=Fntl/Fob×250/Fne??(1) Fntl=Ftl×Kt??(2) Fne=Fe×Kt??(3) 0.4<kt<0.95??(4).

Abstract: A monocentric lens-based multi-scale imaging system is disclosed. Embodiments of the present invention comprise a monocentric lens as an objective lens that collects light from a scene. Monocentric lenses in accordance with the present invention include a spherical central lens element and a plurality of lens shell sections that collectively reduce at least one of spherical and chromatic aberration from the magnitude introduced by the spherical lens element itself. A plurality of secondary lenses image the scene through the objective lens and further reduce the magnitude of aberrations introduced by the objective lens. A plurality of sensor arrays converts optical sub-images of the scene into a plurality of digital images, which can then be used to form a composite image of the scene.

Abstract: The invention relates to a relay set for an endoscope that includes a plurality of relay sets of the same type, having two plano-convex rod lenses which face one another with their planar end surfaces, and an achromat that is arranged between these rod lenses, particularly in a central aperture plane of said relay set. Said achromat takes the form of an arrangement of at least two lenses which have different refractive indices and Abbe numbers, and is located at a distance from the rod lenses. The invention also relates to a corresponding endoscope. The claimed relay set is improved in that one lens of said achromat consists of ED glass that has an Abbe number of at least 75, in particular at least 77.

Abstract: An endoscope includes an image transmission device in a shank for transmitting an image from the distal end to the proximal end of the endoscope and an image erecting device for erecting an image registered by means of the endoscope. The image erecting device has a first face for angle-dependent reflection and a second face for angle-dependent reflection. The image erecting device is arranged and embodied in such a way that light for image erecting is successively reflected at the first reflective face, passed through the first reflective face and through the second, reflective face and reflected at the second reflective face.

Abstract: A light modulation device side lens group has different powers in the longitudinal direction and the lateral direction of a liquid crystal panel. Therefore, as the entire system of the optical projection system, the light modulation device side lens group has different magnification in the longitudinal and lateral directions. Therefore, it is possible to make the aspect ratio of an image of the liquid crystal panel different from the aspect ratio of an image projected on a screen. That is, conversion can be performed on an aspect ratio. At this time, a distance p between each focus or a diaphragm and the screen SC side end surface of the light modulation device side lens group satisfies the conditional expressions, so it is possible to achieve a predetermined or higher telecentricity in both states, that is, a first operating state and a second operating state.

Abstract: A relay zoom system includes, in order from an object side, a first lens group having a positive refractive power and a second lens group having a positive refractive power. Furthermore, in the relay zoom system, the first lens group and the second lens group are each made up of at least two positive lenses and one negative lens. The first lens group and the second lens group in the relay zoom system are configured so as to move along an optical axis when magnification is varied from a lower magnification edge state to a higher magnification edge state.

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: The present invention provides a projection apparatus including an image generation device and a projection lens. The image generation device has a light valve, and generates a light. The projection lens includes a first lens group having an optical axis and a second lens group disposed between the first lens group and the light valve. The light generated from the light valve penetrates through the second lens group and forms an intermediate image between the first lens group and the second lens group. The intermediate image penetrates through the first lens group to form a projection image. A center of the projected image and a center of the light valve are disposed at a first side of the optical axis, and a center of the intermediate image is disposed at a second side of the optical axis different from the first side.

Abstract: By suitably correcting a secondary spectrum, a clear, bright optical image is obtained. Provided is a rigid-scope optical system including: an objective optical system; and at least one relay optical systems that are formed of positive front groups, middle groups, and back groups in this order from an entrance side and that reimage an optical image imaged at imaging planes at the entrance side onto imaging planes at an exit side, wherein axial chromatic aberration between two wavelengths is corrected by an optical system other than the diffractive optical element, and axial chromatic aberration between the two wavelengths and another wavelength is corrected by the diffractive optical element.

Abstract: An incident-light fluorescent illumination device includes: a light source emitting illumination light; a collector lens receiving the illumination light from the light source; a fly-eye lens optical system receiving the illumination light from the collector lens; an objective emitting the illumination light to a sample surface; and a relay optical system arranged between the fly-eye lens optical system and the objective. The fly-eye lens optical system includes a first fly-eye lens surface and a second fly-eye lens surface each having a plurality of lens elements. The incident-light fluorescent illumination device satisfies the conditional expression of 0.3?D0/Lob?0.75 where: D0 indicates the distance between a conjugate position with the second fly-eye lens surface through the relay optical system and a pupil position of the objective, and Lob indicates a parfocalizing distance of the objective.

Abstract: Described herein is a light directing assembly for use in an object analysis system. The light directing assembly includes a plurality of optical relay assemblies. Each optical relay assembly includes at least one optical element configured to relay an interrogation beam from a light transmission system to an object and relay a return beam from the object to the light transmission system, the return beam being generated by reflection or back scattering of the interrogation beam by the object. Each optical relay assembly defines an interrogation angle at which the interrogation beam relayed by the optical relay assembly reaches the object, and an optical path length being the distance from the light transmission system to the object travelled by an interrogation beam via the optical relay assembly.

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: Three or more devices can be connected to a microscope and can be used simultaneously. Provided is a microscope connecting unit including a microscope connection port that is connected to a microscope used to observe a sample; three or more unit connection ports to which a stimulating unit that irradiates the sample with light or a confocal observation unit or an image capturing unit that detects light generated at the sample is connectable; and two or more light-path combining units that are disposed between the microscope connecting port and the unit connection ports and that combine light paths optically connecting the microscope with the confocal observation unit, the stimulating unit, and the image capturing unit.

Abstract: Provided is a wavelength selective switch, which includes: an input/output unit; a dispersive portion; a deflection portion; and an ovalization relay optical system. In the input/output unit, input/output portions are two-dimensionally arranged. The dispersive portion is capable of dispersing signal light along a first plane. The deflection portion deflects the signal light. The ovalization relay optical system condenses the signal light beams on to a first conjugate point. The ovalization relay optical system makes a beam waist forming position along a first direction coincide with the first conjugate point. The ovalization relay optical system condenses signal light, in a second direction, onto a first condensing point. The ovalization relay optical system makes the first condensing point conjugate to the first conjugate point. The ovalization relay optical system ovalizes the beam shape of the signal light beams incident on the deflection element.

Abstract: An infinity-conjugate lens relay with a moving first lens is used to select a plane of interest from an image volume. This plane can be selected so that the image is corrected for spherical aberration due to non-ideal imaging conditions. This effectively will allow for deeper, corrected imaging for high power microscopes. Using an infinity-conjugate relay, this device has an ideal “bypass” mode for regular imaging without correction. The device also utilizes software that automatically controls the device for correcting live images.

Abstract: An imaging lens having reduced susceptibility to thermally-induced stress birefringence for imaging an object plane to an image plane; comprising: an aperture stop positioned between the object plane and the image plane; a first group of lens elements located on the object plane side of the aperture stop; and a second group of lens elements located on the image plane side of the aperture stop; wherein the lens elements immediately adjacent to the aperture stop are fabricated using glasses having a negligible susceptibility to thermal stress birefringence as characterized by a thermal stress birefringence metric; and wherein the other lens elements in the first or second groups of lens elements are fabricated using glasses having at most a moderate susceptibility to thermal stress birefringence as characterized by the thermal stress birefringence metric.

Abstract: Spherical aberration is the primary cause of lose of signal while imaging deeper into a sample. Spherical aberration is corrected in the imaging path of a non-descanned detection system (such as a multi-photon microscope). This corrects the illumination spot for artifacts caused by imaging deep into a sample. One exemplary advantage to this instrument is that it allows deeper and brighter imaging.

Abstract: An imaging system for viewing both flat and angled surfaces of a test element, such as the end faces of both PC and APC optical fibers. A light source provides light to the angled surface, while lensing directs a portion of the original light to the angled surface at a second acute angle. A collector, e.g. photodetector, lenses or human eye, receives the portion of the light reflected from the angled surface and generates an image thereof. An annulus is provided in the optical path for managing the light. The annulus includes a transparent outer ring enabling the portion of the light to pass from the light source to the surface at the second acute angle; a central transparent section enabling light reflected from the angled surface to pass to the collector along the longitudinal optical axis; and a first light-blocking ring between the outer ring and the central section for blocking excess light from the light source and reflected from the end surface.

Abstract: Wide-angle, deep-field, close-focusing optical systems are disclosed. According to one aspect, the optical system comprises a negative lens unit and a relay lens. The negative lens unit accepts radiation from an object in space. The relay lens is coupled to the negative lens unit. The negative lens unit and the relay lens are aligned on an optical axis in that order. The negative lens unit forms a first image on the relay lens to form a final image at a final image plane at a distance from the relay lens. The relay lens may comprise a zoom lens or zoom lens components, which may be movable.

Abstract: An objective having a plurality of optical elements arranged to image a pattern from an object field to an image field at an image-side numerical aperture NA>0.8 with electromagnetic radiation from a wavelength band around a wavelength ? includes a number N of dioptric optical elements, each dioptric optical element i made from a transparent material having a normalized optical dispersion ?ni=ni(?0)?ni(?0+1 pm) for a wavelength variation of 1 pm from a wavelength ?0. The objective satisfies the relation ? ? i = 1 N ? ? ? ? n i ? ( s i - d i ) ? ? 0 ? NA 4 ? A for any ray of an axial ray bundle originating from a field point on an optical axis in the object field, where si is a geometrical path length of a ray in an ith dioptric optical element having axial thickness di and the sum extends on all dioptric optical elements of the objective. Where A=0.2 or below, spherochromatism is sufficiently corrected.

Abstract: Provided is a wavelength selective switch, which includes: an input/output unit; a dispersive portion; a deflection portion; and an ovalization relay optical system. In the input/output unit, input/output portions are two-dimensionally arranged. The dispersive portion is capable of dispersing signal light along a first plane. The deflection portion deflects the signal light. The ovalization relay optical system condenses the signal light beams on to a first conjugate point. The ovalization relay optical system makes a beam waist forming position along a first direction coincide with the first conjugate point. The ovalization relay optical system condenses signal light, in a second direction, onto a first condensing point. The ovalization relay optical system makes the first condensing point conjugate to the first conjugate point. The ovalization relay optical system ovalizes the beam shape of the signal light beams incident on the deflection element.

Abstract: An illumination optical apparatus guides to an illumination object a light beam emitted from a light source. The illumination optical apparatus includes an enlarging optical system, disposed between the light source and the illumination object, and a reduction optical system, disposed between the enlarging optical system and the illumination object. The enlarging optical system is formed so that an image plane is disposed between the light source and the illumination object.

Abstract: Imaging optics having reduced susceptibility to thermally-induced stress birefringence for imaging an object plane to an image plane; comprising an aperture stop positioned between the object plane and the image plane; a first group of optical elements located on the object plane side of the aperture stop; and a second group of optical elements located on the image plane side of the aperture stop. The optical elements in the first and second groups that are immediately adjacent to the aperture stop are refractive lens elements fabricated using optical materials having a negligible susceptibility to thermal stress birefringence, and the other optical elements are a combination of reflective optical elements and refractive lens elements fabricated using optical materials having at most a moderate susceptibility to thermal stress birefringence.