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).

An imaging device outputs time series images that include multiple captured images that capture over time the surface of the object to be measured. On the optical path extending from the object to be measured, through a lens equipped on the imaging device and up to the imaging surface, the optical path bending member is interposed in a part of the optical path between the object to be measured and a lens. The optical path bending member bends the light traveling from the lens to the imaging surface so as to tilt the light in a direction such that the direction of travel thereof approaches the optical axis of the lens. This abnormality determination device utilizes the in-plane displacement and out-of-plane displacement calculated from the time series images to determine abnormalities in the measured object.

An imaging device outputs time series images that include multiple captured images that capture over time the surface of the object to be measured. On the optical path extending from the object to be measured, through a lens equipped on the imaging device and up to the imaging surface, the optical path bending member is interposed in a part of the optical path between the object to be measured and a lens. The optical path bending member bends the light traveling from the lens to the imaging surface so as to tilt the light in a direction such that the direction of travel thereof approaches the optical axis of the lens. This abnormality determination device utilizes the in-plane displacement and out-of-plane displacement calculated from the time series images to determine abnormalities in the measured object.

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.

An optical system includes an incident part, a first reflective surface, a second reflective surface, a third reflective surface, and an exit part. The incident part is rotationally symmetric around a central axis. Incident light from the incident part intersects the central axis and enters the first reflective surface. Reflected light from the first reflective surface intersects the central axis and enters the second reflective surface. Reflected light from the second reflective surface enters the third reflective surface.

An optical system includes an incident part, a first reflective surface, a second reflective surface, a third reflective surface, and an exit part. The incident part is rotationally symmetric around a central axis. Incident light from the incident part intersects the central axis and enters the first reflective surface. Reflected light from the first reflective surface intersects the central axis and enters the second reflective surface. Reflected light from the second reflective surface enters the third reflective surface.

A fundus imaging system comprises: a reflection mirror that reflects a light beam incident on the reflection mirror after passing through a first focus so as to cause the light beam to pass through a second focus; a two-dimensional scanning unit that is disposed at a position that coincides with a position of the first focus of the reflection mirror and that reflects a light beam incident on the two-dimensional scanning unit so as to perform scanning with the light beam in two-dimensional directions; and a compensating unit that compensates for illuminance ununiformity of a light beam illuminating the retina, the illuminance ununiformity resulting from unevenness of a ratio of an angular change of a light beam emitted from the first focus during scanning of the two-dimensional scanning unit to an angular change of a light beam incident on the second focus resulting from being reflected by the reflection mirror.

A fundus imaging system comprises: a reflection mirror that reflects a light beam incident on the reflection mirror after passing through a first focus so as to cause the light beam to pass through a second focus; a two-dimensional scanning unit that is disposed at a position that coincides with a position of the first focus of the reflection mirror and that reflects a light beam incident on the two-dimensional scanning unit so as to perform scanning with the light beam in two-dimensional directions; and a compensating unit that compensates for illuminance ununiformity of a light beam illuminating the retina, the illuminance ununiformity resulting from unevenness of a ratio of an angular change of a light beam emitted from the first focus during scanning of the two-dimensional scanning unit to an angular change of a light beam incident on the second focus resulting from being reflected by the reflection mirror.

A fundus imaging system comprises: a first reflection mirror that reflects a light beam passing through a first focus of the first reflection mirror to pass through a second focus; a two-dimensional scanning unit that is disposed at a position of the first focus and reflects a light beam incident on the two-dimensional scanning unit so as to scan the retina with the light beam in two-dimensional directions; and a second reflection mirror that reflects a light beam passing through a third focus so as to cause the light beam to pass through a fourth focus, the second reflection mirror being disposed so that a position of the third focus coincides with a position of the second focus, wherein a position of the pupil of the subject is disposed so as to coincide with a position of the fourth focus.

A system and method of generating white light for a projection system in a compact form factor using laser diodes, a reflection system, and a phosphor target. Light emitted from the laser diodes can be directed towards a region of the phosphor target, where the phosphor target is excited and emits light in a desired spectrum in all directions. Some emitted light is collected by a collection lens. The emitted light collected by the collection lens can be combined with light from the original laser diodes to create white light for use in the projection system. Light emitted in a direction away from the collection lens can be redirected to the collection lens by the reflection system that employs a curved reflector on one side of the phosphor target and a flat reflector on the opposite side of the phosphor target.