Abstract: A light source apparatus configured to emit first light and second light includes a wavelength reference device, a splitter, a first detector, a second detector, and a control unit. The control unit includes a correction unit configured to reduce from a detection signal detected by the first detector a portion included in the detected signal and related to an intensity of the second light incident on the first detector from the splitter, and configured to reduce from a detection signal detected by the second detector a portion included in the detected signal and related to an intensity of the first light incident on the second detector from the splitter. The control unit controls a wavelength of the first light and a wavelength of the second light based on signals from the correction unit.

Abstract: The present invention provides a measurement apparatus which measures a distance between a reference surface and a surface to be measured, including a wavelength reference element configured to include a gas cell in which a plurality of types of gases having absorption lines different from each other are sealed, and a processing unit configured to set a wavelength of light emitted by a light source to a plurality of different wavelengths corresponding to a plurality of different absorption lines by using the wavelength reference element, control a phase detection unit to detect a phase corresponding to an optical path length between the reference surface and the surface to be measured for each of the plurality of different wavelengths, and perform processing of obtaining the distance.

Abstract: A light source apparatus configured to emit first light and second light includes a wavelength reference device, a splitter, a first detector, a second detector, and a control unit. The control unit includes a correction unit configured to reduce from a detection signal detected by the first detector a portion included in the detected signal and related to an intensity of the second light incident on the first detector from the splitter, and configured to reduce from a detection signal detected by the second detector a portion included in the detected signal and related to an intensity of the first light incident on the second detector from the splitter. The control unit controls a wavelength of the first light and a wavelength of the second light based on signals from the correction unit.

Abstract: The present invention provides a measurement apparatus which measures a distance between a reference surface and a surface to be measured, including a wavelength reference element configured to include a gas cell in which a plurality of types of gases having absorption lines different from each other are sealed, and a processing unit configured to set a wavelength of light emitted by a light source to a plurality of different wavelengths corresponding to a plurality of different absorption lines by using the wavelength reference element, control a phase detection unit to detect a phase corresponding to an optical path length between the reference surface and the surface to be measured for each of the plurality of different wavelengths, and perform processing of obtaining the distance.

Abstract: A method of measuring an optical characteristic of an optical system using a measurement apparatus, comprises determining a position of each of object points by arranging, on a side of the object plane, an object point measurement device array, and sequentially inserting the object point measurement devices in an optical path, determining a position of each of image points by arranging, on a side of the image plane, an image point measurement device array, and sequentially inserting the image point measurement devices in the optical path, calculating an error attributed to the measurement apparatus based on the positions of object points and the positions of the image points, obtaining a measured value by measurement to obtain information representing the optical characteristic of the optical system using the measurement apparatus, and correcting the measured value based on the error.

Abstract: The disclosure describes obtaining a first reference wavefront generated from a object plane mask slit, obtaining a second reference wavefront generated from a first image plane mask slit, measuring a wavefront of a target optical system including a reference wavefront error, and subtracting the first and the second reference wavefronts from the target optical system include the reference wavefront error.

Abstract: A method of measuring an optical characteristic of an optical system using a measurement apparatus, comprises determining a position of each of object points by arranging, on a side of the object plane, an object point measurement device array, and sequentially inserting the object point measurement devices in an optical path, determining a position of each of image points by arranging, on a side of the image plane, an image point measurement device array, and sequentially inserting the image point measurement devices in the optical path, calculating an error attributed to the measurement apparatus based on the positions of object points and the positions of the image points, obtaining a measured value by measurement to obtain information representing the optical characteristic of the optical system using the measurement apparatus, and correcting the measured value based on the error.

Abstract: A measurement method for measuring a wavefront aberration of a target optical system using an interference pattern formed by a light from a first image side slit, and a light from a second image side slit, the first and second image side slits being located at an image side of the target optical system, the first image side slit having, in a shorter direction, a width equal to or smaller than a diffraction limit of the target optical system, and the second image side slit having, in a shorter direction, a width greater than the diffraction limit of the target optical system includes the steps of obtaining three or more primary wavefronts of the target optical system from different measurement directions, and calculating a wavefront aberration of the target optical system based on the three or more primary wavefronts obtained by the obtaining step.

Abstract: A measurement method for measuring a wavefront aberration of a target optical system using an interference pattern formed by a light from a first image side slit, and a light from a second image side slit, the first and second image side slits being located at an image side of the target optical system, the first image side slit having, in a shorter direction, a width equal to or smaller than a diffraction limit of the target optical system, and the second image side slit having, in a shorter direction, a width greater than the diffraction limit of the target optical system includes the steps of obtaining three or more primary wavefronts of the target optical system from different measurement directions, and calculating a wavefront aberration of the target optical system based on the three or more primary wavefronts obtained by the obtaining step.

Abstract: A measurement method for measuring a wavefront aberration of a target optical system using an interference pattern formed by a light from a first image side slit, and a light from a second image side slit, the first and second image side slits being located at an image side of the target optical system, the first image side slit having, in a shorter direction, a width equal to or smaller than a diffraction limit of the target optical system, and the second image side slit having, in a shorter direction, a width greater than the diffraction limit of the target optical system includes the steps of obtaining three or more primary wavefronts of the target optical system from different measurement directions, and calculating a wavefront aberration of the target optical system based on the three or more primary wavefronts obtained by the obtaining step.

Abstract: A measurement method measures a wavefront aberration of a target optical system using an interference pattern formed by lights from first and second image side slits. The first image side slit has a width equal to or smaller than a diffraction limit of the target optical system. The measurement method includes the steps of obtaining a first and second wavefronts having wavefront aberration information of the target optical system in ±45° directions relative to the polarization direction of the light, and calculating wavefront aberration of the target optical system based on the first and second wavefronts of the target optical system obtained by the obtaining step.

Abstract: A measurement method for measuring a wavefront aberration of a target optical system using an object plane side slit includes the step of removing a reference wavefront error from a wavefront aberration of the target optical system obtained from an interference pattern formed by interference between light from the first image plane side slit and light from the second image plane side slit. The reference wavefront error is contained in an object plane side reference wavefront generated from the first object plane side slit and an image plane side reference wavefront generated from the first image plane side slit.

Abstract: A measurement method for measuring a wavefront aberration of a target optical system using an interference pattern formed by a light from a first image side slit, and a light from a second image side slit, the first and second image side slits being located at an image side of the target optical system, the first image side slit having, in a shorter direction, a width equal to or smaller than a diffraction limit of the target optical system, and the second image side slit having, in a shorter direction, a width greater than the diffraction limit of the target optical system includes the steps of obtaining three or more primary wavefronts of the target optical system from different measurement directions, and calculating a wavefront aberration of the target optical system based on the three or more primary wavefronts obtained by the obtaining step.

Abstract: A measurement method measures a wavefront aberration of a target optical system using an interference pattern formed by lights from first and second image side slits. The first image side slit has a width equal to or smaller than a diffraction limit of the target optical system. The measurement method includes the steps of obtaining a first and second wavefronts having wavefront aberration information of the target optical system in ±45° directions relative to the polarization direction of the light, and calculating wavefront aberration of the target optical system based on the first and second wavefronts of the target optical system obtained by the obtaining step.