Abstract: A point diffraction interferometer measures optical performance of a target optical system based on a light intensity distribution of an interference fringe through an interference between a wave front that passes the target optical system and a reference wave front generated from a pinhole, wherein the pinhole satisfies 1.05?ellipticity?1.16, where the ellipticity is defined as a diameter of a pinhole in a direction perpendicular to a linear polarization direction of light incident upon the pinhole, divided by a diameter of the pinhole in the linear polarization direction.

Abstract: A measuring apparatus for measuring optical performance of a test optics by using light includes a first member for generating a first ideal wave front, a second member for generating a second ideal wave front and a test wave front that reflects the optical performance of the test optics, and a detector for detecting an interference fringe between the test wave front and the second ideal wave front that passes the second member, wherein the first member and/or the second member include a first membrane having a first aperture for diffracting the light, and a second membrane having a second aperture for diffracting the light that has passed the first aperture, the second membrane being spaced from the first membrane so that the first and second apertures overlap each other.

Abstract: An exposure apparatus that exposes a pattern of an original onto a substrate includes a condenser optical system configured to split light from a light source into plural rays, to condense the plural rays at different positions on the original, and to make a central part of each of the plural rays that illuminate the original darker than a periphery at the Fourier transform plane with respect to the original, and a projection optical system configured to project the pattern of the original onto the substrate.

Abstract: An immersion optical system that condenses light from a light source toward a first surface includes a lens having a concave lens surface closest to the first surface, a liquid being filled in a space between the concave lens surface and the first surface, wherein a conditional equation d>L/[2×tan {arcsin(NA/ni)}] is met, where d is a distance between a first point and a second point when the distance becomes maximum between the first point on the concave lens surface and the second point on the first surface in a direction substantially orthogonal to the first surface, L/2 is a maximum distance from the second point to an edge of an irradiation area of the light on a first surface, NA is a numerical aperture of the immersion optical system, and ni is a refractive index of the liquid.

Abstract: A tilt angle detection device and method which generates, as a first push-pull signal, a difference between light reception signals corresponding to two light receiving surfaces of one side of a photodetector, which are divided along the track tangent direction; generates, as a second push-pull signal, a difference between the light reception signals corresponding to two light receiving surfaces of the other side of the photodetector; and generates a tilt signal that indicates a tilt angle defined by a normal on the recording surface of the optical recording medium at a position of irradiation of the laser beam and the optical axis of the laser beam in accordance to a difference between amplitudes of the first and second push-pull signals.

Abstract: A focus servo device is for focusing a light irradiated from a light source onto a recording medium surface via an objective lens. Assuming that a wavelength of the light is ?, a numerical aperture of the objective lens is NA, an average run length period of the recording medium standardized with ?/NA is RL, the track pitch standardized with ?/NA is TP, and the capture range of said focus servo device is CR [?m], the following equation applies: 0.114/(RL?0.72)+0.84?CR?18000(TP?0.69)5+3.13.

Abstract: An exposure apparatus for exposing a pattern of an mask onto a plate to be exposed, said exposure apparatus includes a cleaning apparatus for cleaning the mask, wherein said cleaning apparatus includes an irradiating part for irradiating a laser beam to the mask, and a polarization controller for controlling a polarization characteristic of the laser beam according to a longitudinal direction of the pattern.

Abstract: An immersion optical system that condenses light from a light source toward a first surface includes a lens having a concave lens surface closest to the first surface, a liquid being filled in a space between the concave lens surface and the first surface, wherein a conditional equation d>L/[2×tan {arcsin(NA/ni)}] is met, where d is a distance between a first point and a second point when the distance becomes maximum between the first point on the concave lens surface and the second point on the first surface in a direction substantially orthogonal to the first surface, L/2 is a maximum distance from the second point to an edge of an irradiation area of the light on a first surface, NA is a numerical aperture of the immersion optical system, and ni is a refractive index of the liquid.

Abstract: A particle remover includes an irradiation unit for irradiating plural lights onto a target from different directions, and for scanning the lights on the target, and a collector for collecting particles carried as a result of scanning of the lights.

Abstract: A focus servo device is for focusing a light irradiated from a light source onto a recording medium surface via an objective lens. Assuming that a wavelength of the light is ?, a numerical aperture of the objective lens is NA, an average run length period of the recording medium standardized with ?/NA is RL, the track pitch standardized with ?/NA is TP, and the capture range of said focus servo device is CR [?m], the following equation applies: 0.114/(RL?0.72)+0.84?CR?18000(TP?0.69)5+3.13.

Abstract: A measuring apparatus for measuring optical performance of a test optics by using light includes a first member for generating a first ideal wave front, a second member for generating a second ideal wave front and a test wave front that reflects the optical performance of the test optics, and a detector for detecting an interference fringe between the test wave front and the second ideal wave front that passes the second member, wherein the first member and/or the second member include a first membrane having a first aperture for diffracting the light, and a second membrane having a second aperture for diffracting the light that has passed the first aperture, the second membrane being spaced from the first membrane so that the first and second apertures overlap each other.

Abstract: A point diffraction interferometer measures optical performance of a target optical system based on a light intensity distribution of an interference fringe through an interference between a wave front that passes the target optical system and a reference wave front generated from a pinhole, wherein the pinhole satisfies 1.05?ellipticity?1.16, where the ellipticity is defined as a diameter of a pinhole in a direction perpendicular to a linear polarization direction of light incident upon the pinhole, divided by a diameter of the pinhole in the linear polarization direction.

Abstract: An information reproducing apparatus(100) is provided with: a focusing device(11a) which makes a signal-reading probe light converge onto an optical recording medium(10); a focus servo device(12) which maintains a focus on a recording layer of the optical recording medium(10) by controlling the focusing device(11a); an offset providing device(14) which provides a predetermined offset to a target value used by the focus servo device(12); and a spherical aberration detecting device(17) which detects a signal indicative of spherical aberration contained in the probe light on the basis of an intensity of a signal reproduced based on a plurality of target values obtained by the offset providing device(14) generated on at least one signal of at least one predetermined spatial frequency recorded on the optical recording medium(10).

Abstract: A tilt angle detection device and method which generates, as a first push-pull signal, a difference between light reception signals corresponding to two light receiving surfaces of one side of a photodetector, which are divided along the track tangent direction; generates, as a second push-pull signal, a difference between the light reception signals corresponding to two light receiving surfaces of the other side of the photodetector; and generates a tilt signal that indicates a tilt angle defined by a normal on the recording surface of the optical recording medium at a position of irradiation of the laser beam and the optical axis of the laser beam in accordance to a difference between amplitudes of the first and second push-pull signals.

Abstract: An optical disk has a recording layer recording information as a row of marks and non-marks alternately appearing in a groove formed at a track pitch of 0.280 &mgr;m or greater and a light transmissive layer formed over the recording layer, to reproduce information due to a light beam having a wavelength in a range of 375 nm to 415 nm and illuminated by an objective lens having a numerical aperture NA in a range of 0.80 to 0.90 through the light transmissive layer to the recording layer. The groove has a depth in a range of 18 nm to 32 nm.

Abstract: An optical disk has a recording layer recording information as a row of marks and non-marks alternately appearing in a groove formed at a track pitch of 0.280 &mgr;m or greater and a light transmissive layer formed over the recording layer, to reproduce information due to a light beam having a wavelength in a range of 375 nm to 415 nm and illuminated by an objective lens having a numerical aperture NA in a range of 0.80 to 0.90 through the light transmissive layer to the recording layer. The groove has a depth in a range of 18 nm to 32 nm.