A catoptric system having a reference axis and including a reflective pattern-source (carrying a substantially one-dimensional pattern) and a combination of only three optical components disposed sequentially to transfer EUV radiation incident the first optical component onto the pattern-source. The combination is disposed in a fixed spatial and optical relationship with respect to the pattern-source, and represents an illumination unit (IU) of a 1D EUV exposure tool that additionally includes a projection optic sub-system configured to form an optical image of the pattern-source on an image plane with the use of only two beams of radiation. These only two beams of radiation originate at the pattern-source from the EUV radiation transferred onto the pattern-source.

A spectrometer with an unobstructed, Schmidt reflector is described. The spectrometer may include a Schmidt corrector and a dispersive element as separate components. Alternatively, the Schmidt corrector and dispersive element may be combined into a single optical component. The spectrometer may further include a field-flattener lens.

A plasma light source with lamp house correction is disclosed. The system may include a pump source configured to generate pump illumination. The pump illumination may be directed, by an elliptical reflector element, to a volume of gas contained within a plasma lamp in order to generate a plasma. The plasma may be configured to generate broadband illumination. The system may also include a correction plate and/or an aspherical elliptical reflector element configured to alter the pump illumination to correct for aberrations introduced by the plasma lamp. The system may also include an additional aspherical correction plate configured to alter the broadband illumination to correct for aberrations introduced by optical elements of the system.

Techniques are disclosed for magnification compensation and/or beam steering in optical systems. An optical system may include a lens system to receive first radiation associated with an object and direct second radiation associated with an image of the object toward an image plane. The lens system may include a set of lenses, and an actuator system to selectively adjust the set of lenses to adjust a magnification associated with the image symmetrically along a first and a second direction. The lens system may also include a beam steering lens to direct the first radiation to provide the second radiation. In some examples, the lens system may also include a second set of lenses, where the actuator system may also selectively adjust the second set of lenses to adjust the magnification along the first or the second direction. Related methods are also disclosed.

An optical assembly guides an output beam of a free electron laser to a downstream illumination-optical assembly of an EUV projection exposure apparatus. The optical assembly has first and a second GI mirrors, each with a structured reflection surface to be impinged upon by the output beam. A first angle of incidence on the first GI mirror is between one mrd and 10 mrad. A maximum first scattering angle is produced, amounting to between 50% and 100% of the first angle of incidence. A second angle of incidence on the second GI mirror is at least twice as large as the first angle of incidence. A maximum second scattering angle of the output beam amounts to between 30% and 100% of the second angle of incidence. The two planes of incidence on the two GI mirrors include an angle with respect to one another that is greater than 45.

A catadioptric lens includes at least two optical elements arranged along an optical axis. Both optical elements are configured as a mirror having a substrate and a highly reflective coating applied to an interface of the substrate. The highly reflective coating extends from the interface of the substrate along a surface normal. At least one of the highly reflective coatings has one or a plurality of layers. The optical total layer thickness of the one layer of the plurality of layers increases radially from the inner area outward.

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 $4<\frac{.Math.{}_I.Math.}{.Math.{}_T.Math.}<30,$
where .sub.I and .sub.T are magnifications of the first portion and the overall projection lens. Optionally, the projection lens may be structured to additionally satisfy $6<\frac{.Math.{}_{\mathrm{II}}.Math.}{.Math.{}_T.Math.}<20,$
where .sub.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.

An optical inspection system that utilizes sub-200 nm incident light beam to inspect a surface of an object for defects is described. The sub-200 nm incident light beam is generated by combining first light having a wavelength of about 1109 nm with second light having a wavelength of approximately 234 nm. An optical system includes optical components configured to direct the incident light beam to a surface of the object, and image relay optics are configured to collect and relay at least two channels of light to a sensor, where at least one channel includes light reflected from the object, and at least one channel includes light transmitted through the object. The sensor is configured to simultaneously detect both the reflected and transmitted light. A laser for generating the sub-200 nm incident light beam includes a fundamental laser, two or more harmonic generators, a frequency doubler and a two frequency mixing stages.

A catadioptric projection lens images a pattern of a mask in an effective object field of the projection lens into an effective image field of the projection lens with electromagnetic radiation with an operating wavelength <260 nm. The projection lens includes a multiplicity of lens elements and a multiplicity of mirrors including at least one concave mirror. The lens elements and mirrors define a projection beam path that extends from the object plane to the image plane and contains at least one pupil plane. The mirrors include a first mirror having a first mirror surface in the projection beam path between the object and pupil planes in the optical vicinity of a first field plane optically conjugate to the object plane. The mirrors also include a second mirror having a second mirror surface in the projection beam path between the pupil and image planes in the optical vicinity of a second field plane that is optically conjugate to the first field plane. The first mirror surface and/or the second mirror surface is a freeform surface.

The invention relates to a catadioptric medical imaging system (1), in particular a surgical microscope (2). During surgery, it may be necessary to gain more information about a surgical cavity (6), in particular the type of tissue (29) at the inside walls (4) of the surgical cavity (6). To solve this problem, the catadioptric medical imaging system (1) according to the invention comprises a camera device (8) and a convex catoptric mirror (20) adapted to be inserted into the surgical cavity (6). The catoptric mirror (20) is mounted on an arm (22) and spaced apart from the camera device (8).