An all-reflective or reflective and cata-dioptric optical system includes a concave primary mirror having a central aperture and a radius, the primary mirror having one of a parabolic, non-parabolic conical, or aspherical surface, a convex secondary mirror facing the primary mirror, the secondary mirror having an aspherical surface, where an optical axis extends from a vertex of the primary mirror to a vertex of the secondary mirror, a concave tertiary mirror arranged behind the primary mirror, the tertiary mirror having one of a parabolic, non-parabolic conical or aspherical surface, a concave quaternary mirror arranged in the central aperture of the primary mirror or behind the primary mirror, the quaternary mirror having one of a spherical, parabolic, non-parabolic conical or aspherical surface, and/or at least one image plane having one or more aggregated sensors. Additional multispectral imaging may utilize beam splitter(s), folding mirror(s), focal length optimizer(s) and/or additional image planes.

There is provided a reflective image-forming optical system which is applicable to an exposure apparatus using, for example, EUV light and which is capable of increasing numerical aperture while enabling optical path separation of light fluxes. In a reflective imaging optical system (6) forming an image of a first plane (4) onto a second plane (7), the numerical aperture on a side of the second plane with respect to a first direction (X direction) on the second plane is greater than 1.1 times a numerical aperture on the side of the second plane with respect to a second direction (Y direction) crossing the first direction on the second plane. The reflecting imaging optical system has an aperture stop (AS) defining the numerical aperture on the side of the second plane, and the aperture stop has an elliptic-shaped opening of which size in a major axis direction (X direction) is greater than 1.1 times that in a minor axis direction (Y direction).

Certain examples relate to a terrestrial terahertz imaging system. In one example, the terrestrial terahertz imaging system has an imaging assembly to form a first image of at least a portion of an object using electromagnetic radiation in a terahertz band of frequencies and a receiver assembly comprising a cryostat. The cryostat contains a detector and reflective cold re-imaging optical components to receive the electromagnetic radiation from the imaging assembly. The reflective cold re-imaging optical components form a second image of at least a portion of the object on the detector. The imaging assembly has reflective optical components arranged in a confocal configuration that is arranged to image at finite conjugates. The reflective cold re-imaging optical components implement a reflective, confocal optical relay. Other examples relate to body and vehicle scanning devices that may be used in security applications.

An optical system including a unity magnification, finite conjugate, all-reflective image relay configured to receive optical radiation representing an input image and to relay the optical radiation via five reflections to an output image plane to provide an output image at the output image plane, the output image being a unity magnification copy of the input image. In certain examples the optical system includes foreoptics configured to produce the input image. The foreoptics and the image relay can be telecentric.

A method includes measuring properties of a three-dimensional topography of a lithographic patterning device, the patterning device including a pattern and being constructed and arranged to produce a pattern in a cross section of a projection beam of radiation in a lithographic projection system, calculating wavefront phase effects resulting from the measured properties, incorporating the calculated wavefront phase effects into a lithographic model of the lithographic projection system, and determining, based on the lithographic model incorporating the calculated wavefront phase effects, parameters for use in an imaging operation using the lithographic projection system.

An all-reflective optical system is described including a concave primary mirror having a central aperture and a radius, the primary mirror having one of a parabolic, non-parabolic conical, or aspherical surface, a convex secondary mirror facing the primary mirror, the secondary mirror having an aspherical surface, where an optical axis extends from a vertex of the primary mirror to a vertex of the secondary mirror, a concave tertiary mirror arranged behind the primary mirror, the tertiary mirror having one of a parabolic, non-parabolic conical or aspherical surface, a concave quaternary mirror arranged in the central aperture of the primary mirror or behind the primary mirror, the quaternary mirror having one of a spherical, parabolic, non-parabolic conical or aspherical surface, and at least one image plane having one or more aggregated sensors, wherein the image plane is positioned at a radial distance from the optical axis that is no more than the radius of the primary mirror.

An optical pulse stretcher includes a first delay optical system including a plurality of concave toroidal mirrors; and a beam splitter including a first surface and a second surface, causing a part of pulse laser light incident on the first surface to be transmitted in a first direction and output as a first beam and another part thereof to be reflected in a second direction and enter the first delay optical system, and causing a part of pulse laser light incident on the second surface from the first delay optical system to be reflected in the first direction and output as a second beam.

An optical module includes a fast-axis mirror that scans a laser beam along a fast-axis, a magnification mirror set formed by three discrete mirrors shaped to magnify the laser beam as it is scanned along the fast-axis and reflect the laser beam after magnification toward a slow-axis mirror that scans the laser beam along the slow-axis, and an Offner mirror relay that receives the laser beam as it is scanned along the slow-axis and reflects the laser beam out an exit aperture. The laser beam as output from the exit aperture is received at an input diffractive grating of a diffractive waveguide, with a user's eye being positioned adjacent an output diffractive grating of the waveguide such that the user's eye views ambient light entering the waveguide from objects within the user's field of view as well as light from the laser beam as it exits the output diffractive grating.

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

There is provided a reflective image-forming optical system which is applicable to an exposure apparatus using, for example, EUV light and which is capable of increasing numerical aperture while enabling optical path separation of light fluxes. In a reflective imaging optical system (6) forming an image of a first plane (4) onto a second plane (7), the numerical aperture on a side of the second plane with respect to a first direction (X direction) on the second plane is greater than 1.1 times a numerical aperture on the side of the second plane with respect to a second direction (Y direction) crossing the first direction on the second plane. The reflecting imaging optical system has an aperture stop (AS) defining the numerical aperture on the side of the second plane, and the aperture stop has an elliptic-shaped opening of which size in a major axis direction (X direction) is greater than 1.1 times that in a minor axis direction (Y direction).