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 that was provided by an illumination system.

The invention provides a wide-aperture spherical primary mirror off-axis afocal optical system, including a primary mirror, a secondary mirror and an aberration compensation mirror group. The primary mirror is a spherical reflector, the secondary mirror are higher-order aspherical reflectors. The primary mirror and the secondary mirror form an off-axis two-mirror system to compress the beam aperture. The aberration compensation mirror group is a coaxial reflective system that is used off-axis. The aberration compensation mirror group has focal power to produce compensation aberrations. The incident beam passes through and is reflected by the primary mirror and secondary mirror sequentially and enters the aberration compensation mirror group thereafter. A spherical reflector is used as the primary mirror, which significantly reduces the development and manufacture cost of the system, and an aberration compensation mirror group is used off-axis to correct residual aberration in the system, which effectively improves imaging quality of the system.

A head mounted display (HMD) includes a display and a pancake lens block. The display with a circular polarizer, comprised of an initial linear polarizer and a first quarter-waveplate with polarizer transmission axis 45 from the waveplate fast axis, emits polarized light. The pancake lens includes a partial reflector, a second quarter-waveplate, and a beam splitting polarizer. The pancake lens receives polarized light from the display. Light propagating through the pancake lens undergoes multiple reflections and transmissions achieved by coordinating changes in polarization of light through these optical elements. To mitigate parasitic light from degrading image quality of the HMD, the fast axis orientation of the first quarter-waveplate is oriented 90 relative to the fast axis orientation of the second quarter-waveplate, and thus the transmission axis of the first polarizer is oriented 90 relative to the transmission axis of the beam splitting polarizer.

An optical imaging system includes a first lens, a second lens, a third lens, a fourth lens, and a fifth lens, disposed in order from an object side, and a first reflection member and a second reflection member, disposed on an object side of the first lens, each having a freeform surface.

An image pickup apparatus including an optical system and an image pickup element. The optical system includes a first refractive surface disposed closest to an object, a first reflection surface, and a second reflection surface. A light receiving surface of the image pickup element is disposed at only one side with respect to the optical axis and at a position closer to the optical axis than an intersection between a straight line connecting an intersection on the first refractive surface and an intersection on an imaginary extension surface of the second reflection surface and an imaginary extension surface of the light receiving surface. Expression 1.5L2/L16.5 is satisfied where L1 is an interval between the first reflection surface and the second reflection surface, and L2 is an interval between the first reflection surface and the light receiving surface.

A head-mounted display comprising (1) an electronic display configured to emit light and (2) a pancake lens optically coupled to the electronic display, the pancake lens comprising a beam splitter configured to (A) transmit a spatial average fraction of the light and (B) reflect an additional spatial average fraction of the light that is less than the spatial average fraction of the light. Various other apparatuses, devices, systems, and methods are also disclosed.

Optical systems are provided. In an embodiment, the optical system includes a first anamorphic optic having a first focal length and a first focal line, where the first focal line is parallel to a cross track direction. A second anamorphic optic has a second focal length and a second focal line, where the second focal length is different than the first first focal length. The second anamorphic optic is positioned such that the first focal line and the second focal line are in about the same location. The first and second anamorphic optics are aligned along an optical signal path, and are configured to provide afocal magnification to a signal beam along an along track direction to produce a magnified beam. A line scan imager includes an objective lens and a linear detector, and the second anamorphic optic is configured to direct the magnified beam at the objective lens.

A catadioptric photographic lens include; a first reflecting mirror, a second reflecting mirror, and a lens group, arranged in order from an object so that light reflected by the first reflecting mirror is reflected by the second reflecting mirror before passing through the lens group and forms an image of the object upon a predetermined image plane wherein; the first and the second reflecting mirror are off-center on the reference plane; reflection surfaces of the first and the second reflecting mirror are rotationally asymmetric aspheric surfaces; the reflection surface of the first reflecting mirror is concave toward the object on the reference plane and on the first orthogonal plane; and the surface closest toward the second reflecting mirror in the lens group having two lenses made from the same optical material as one another is a rotationally asymmetric aspheric surface.

An optical system includes a first optical element including a first reflecting region having a convex shape toward an enlargement side, a second optical element having a reduction-side surface having a convex shape toward the enlargement side, and a third optical element having an enlargement-side surface having a convex shape toward the enlargement side, wherein the reduction-side surface of the second optical element or the enlargement-side surface of the third optical element includes a second reflecting region, wherein the third optical element includes a refracting region having positive power, and wherein light from the enlargement side proceeds to a reduction side sequentially through a refracting region of the first optical element, the second reflecting region, the first reflecting region, a refracting region of the second optical element, and the refracting region of the third optical element.

An optical system includes a first optical element including a refractive surface convex to an enlargement side, a second optical element including a catadioptric surface convex to the enlargement side, a third optical element including a reflective surface of a concave shape with respect to light incident thereon, and a fourth optical element that is a refractive element having positive power, wherein light from the enlargement side travels to a reduction side via the refractive surface, a reflective region of the catadioptric surface, the refractive surface, the reflective surface, the refractive surface, a refractive region of the catadioptric surface, and the fourth optical element in succession, and wherein a medium between the refractive surface and the reflective surface has a refractive index lower than that of the first optical element.