Abstract: Disclosed are a spectacle lens optical characteristics measuring method and a lens meter in which measurement beams are not intercepted by lens pressers. The left and right lenses of a pair of spectacles are point-supported by lens rest shafts at some midpoints in the optical paths of a pair of left and right measurement optical systems, and the spectacle frame for the lenses is held by a pair of frame retaining plates from the front and rear sides. In this state, the spectacle lenses are pressed against lens rest shafts by lens presser shafts to be thereby supported, whereby the way the spectacle frame is held by the frame retaining plates is corrected.

Abstract: In a projection optical system for projecting and transferring a pattern on a projection original R onto a photosensitive substrate W, one or a plurality of lenses having an in-homogeous radial refractive index about the optical axis are used, while one or a plurality of aspheric surfaces for correcting the aberration resulting from the in-homogeousness in refractive index of lenses are provided.

Abstract: An ophthalmic measuring device for obtaining three-dimensional information of an eye to be examined without time lag by projecting pulsed light chirped in such a manner that color is continuously changed from the leading end through the tail end of a pulsed light with time on the eye to be examined, cutting out the pulsed light reflected from the eye to be examined at a predetermined timing by a shutter, and obtaining spectroscopic distribution characteristic of the cut-out image by a spectroscopic unit.

Abstract: The invention provides a lens checking apparatus with which it is possible to automate the optical end control of ophthalmic lenses, especially contact lenses.

Abstract: A method and apparatus for measuring a wave front aberration of a projection lens with high precision and a related calibration method. The apparatus includes: either a light source and an element producing a first point source in combination with the light source or a first point source generating part; a magnifying projection optical system projecting and magnifying a point image of the first point source projected by a test object; a detector detecting the magnified point image projected and magnified by the magnifying projection optical system; a supporting member supporting the magnifying projection optical system and the detector; a calculating part calculating a wave front aberration; and either a second point source producing element or a second point source generating part.

Abstract: The present invention relates to an apparatus for measuring a slant angle in a solid immersion lens. In a near-field optical data storage head for storing/reading data using a solid immersion lens (SIL), a parallel light is formed within the plane of the solid immersion lens and the slant angle of the parallel light is then measured using the angle measurement principle of the autocollimator in order to measure the slant angle of the solid immersion lens. For this, the present invention includes an optical system for generating the parallel light within the solid immersion lens, and a unit for measuring the slant angle of the solid immersion lens using a location detection unit. An incident light becomes the parallel light by the optical system and the curved face of the solid immersion lens. The reflected light is also focused on the location detection unit. The location detection unit converts the reflection angle of the reflecting light into a location value to calculate the angle value.

Abstract: An apparatus for testing and evaluating the condition of an endoscope. The apparatus includes a guide tube dimensioned to accommodate an endoscope, the guide tube having a proximal end, a distal end, and an axis. The apparatus also includes a lens assembly at the proximal end, the lens assembly defining an eyepiece, and an endoscope support disposed in the guide tube. The lens assembly has an optical axis aligned with the guide tube axis. The endoscope support is slidably movable within the guide tube along the guide tube axis. The apparatus may also include a manually-operable device to aid in moving the endoscope support, such as a ratchet wheel rotatably disposed in a wall of the guide tube which engages a groove disposed along a length of the endoscope support, such that when the ratchet wheel is manually rotated, the endoscope support is moved within the guide tube.

Abstract: A position detecting apparatus and a library apparatus that have a flag and a sensor for detecting the flag can shorten time required to perform a position detecting process. The position detecting apparatus comprises a flag 50 and a CCD sensor 36, the flag 50 being provided in a cabinet 23 or a magnetic tape recording-playing apparatus 24 and being formed of a first white part 51 and a second white part 52 with high reflectivity of light and a black part 53 with low reflectivity of light, and the CCD sensor 36 being provided in a medium holding mechanism 30 and detecting optically the first white part 51, the second white part 52 and the black part 53 in the flag 50. The first white part 51 and the second white part 52 are formed as a pair of right isosceles triangles and are positioned symmetrically with respect to an axis of the flag. Furthermore, the CCD sensor 36 is formed of a line type CCD sensor so as to detect the flag 50 linearly.

Abstract: A spectacle lens image sensing processing apparatus irradiates the convex surface of a lens to be examined with light from a light source, projects an image of the convex surface onto a reflection screen placed on the concave surface side of the lens. The apparatus senses the image of the convex surface, projected on the reflection screen, by using an image sensing unit, and performs image processing for the image of the convex surface sensed by the image sensing unit by using an image processing unit, thereby detecting optical characteristics of the lens. The image sensing unit is placed together with the light source on the convex surface side of the lens. The image of the convex surface of the lens is reflected by the reflection screen to return to the convex surface side of the lens, thereby forming the image on the image sensing unit. A spectacle lens positioning method is also disclosed.

Abstract: A lens meter capable of easily measuring optical characteristics of far and near viewing sections of a multifocal lens to obtain optical characteristics of a multifocal lens. The lens meter comprises a first measurement optical system having a first measurement optical axis, for measuring optical characteristics of a far viewing section of a multifocal lens, and a second measurement optical system having a second measurement optical axis which is different from the first measurement optical axis, for measuring optical characteristics of a near viewing section of the multifocal lens.

Abstract: A line-and-space type first pattern and a roughly rectangular second pattern are joined in a rough comb shape to prepare a joint pattern. The first pattern is constituted of a plurality of line patterns each having a width along the direction of its shorter side set to a dimension that does not allow separation/resolution in the field of view of an optical length measuring machine. The second pattern has external dimensions that allow separation/resolution in the field of view of the optical length measuring machine. Such joint patterns are positioned over a distance that allows separation/resolution in the field of view of the optical length measuring machine from each other with the line portions of the first patterns extending outward and achieving a symmetrical positional relationship with together. This pattern is then transferred and formed onto a wafer using a stepper.

Abstract: An apparatus for measuring eccentricity of an optical lens includes a rotary lens holder which supports a first lens surface of an optical lens by vacuum aspiration; a first determining device for determining whether a curvature center of a central portion of the first lens surface is positioned on the rotational axis; a second determining device for determining whether a curvature center of a peripheral portion of the first lens surface is positioned on the rotational axis; and an eccentricity detection device which detects an eccentricity of the optical lens with respect to the rotational axis to calculate an eccentricity of a vertex of the first lens surface with respect to the radial center of the optical lens, including a detector contacts a rim of the optical lens to detect the eccentricity of the optical lens with respect to the rotational axis.

Abstract: A method of determining aberration of an optical imaging system comprises measuring at least one parameter, such as position of best-focus and/or lateral position, of an image formed by the imaging system. This is repeated for a plurality of different illumination settings of the imaging system, and from these measurements at least one coefficient, representative of aberration of said imaging system, is calculated.

Abstract: An apparatus for inspecting a collimator including a pigtail to which a fiber is connected to transmit an optical signal, a GRIN lens coaxially arranged with the pigtail, a glass tube accommodating and supporting the pigtail and the GRIN lens, and a metal sleeve protecting the glass tube, comprising an inspection table; a grip part provided on the inspection table, and gripping the collimator to be inspected; a first camera provided over the grip part having an axis perpendicular to a length of the collimator, and photographing the collimator along the length of the collimator; a second camera arranged coaxially with the collimator on the inspection table, and photographing the collimator perpendicular to an axis of the collimator; and a displaying part connected to the first and second camera, and displaying pictures transmitted from the first and second cameras.

Abstract: The evaluation method comprises a step (S11) of setting an aberration polynomial that generally expresses the aberration of the imaging optical system as a function of the image plane coordinates and pupil coordinates, a measurement step (S12) of measuring the wavefront aberration of the imaging optical system for a plurality of points in the image plane of the imaging optical system, an approximation step (S13) of approximating a specified polynomial as a function of the pupil coordinates to the wavefront aberration obtained in the measurement step, and a step (S14) of determining the coefficients of the respective terms of the aberration-polynomial on the basis of the coefficients of the respective terms in the specified polynomial obtained in the approximation step.

Abstract: A projection lens distortion error map is created using standard overlay targets and a special numerical algorithm. A reticle including a 2-dimensional array of standard overlay targets is exposed several times onto a photoresist coated silicon wafer using a photolithographic stepper. After exposure, the overlay targets are measured for placement error using a conventional overlay metrology tool. The resulting overlay error data is then supplied to a software program that generates a lens distortion error map for the photolithographic projection system.

Abstract: An intraocular lens inspection method including: a process of extracting an intraocular lens for inspection for selecting an intraocular lens; this lens is next, in high temperature liquid immersion process, immersed in physiological saline and kept for a specific amount of time at high temperature that would not deteriorate the lens; then in low-temperature liquid immersion process, the lens is removed and transferred to physiological saline kept at low temperature, which is approximately the temperature when clinically used, and the lens is observed macroscopically; and then in inspection process the lens is put in a chamber kept at the same low temperature, its surface is washed and observed by a microscope, and after observation, the lens is returned to its original state, and when the changes are observed over time and consistent glistenings are detected with each observation, it is judged that clinically analogous glistenings will develop.

Abstract: An intraocular lens inspection method including: a process of extracting an intraocular lens for inspection for selecting an intraocular lens; this lens is next, in high temperature liquid immersion process, immersed in physiological saline and kept for a specific amount of time at high temperature that would not deteriorate the lens; then in low-temperature liquid immersion process, the lens is removed and transferred to physiological saline kept at low temperature, which is approximately the temperature when clinically used, and the lens is observed macroscopically; and then in inspection process the lens is put in a chamber kept at the same low temperature, its surface is washed and observed by a microscope, and after observation, the lens is returned to its original state, and when the changes are observed over time and consistent glistenings are detected with each observation, it is judged that clinically analogous glistenings will develop.

Abstract: A photomask is useful in measuring the aberration of an optical lens. The photomask includes a transparent substrate, a first opaque pattern formed on a first surface of the transparent substrate and defining a plurality of apertures that expose the first surface, and a second opaque pattern formed on the second surface of the transparent substrate. The photomask is placed in an exposure apparatus between a light source of the exposure apparatus and an optical lens whose aberration is to be measured. A photoresist layer on a wafer is exposed through the photomask and the pupil of the optical lens to form a first pattern on the wafer corresponding to the second opaque pattern of the photomask. The aberration of the pupil of the optical lens is evaluated based on the relative location at which the first pattern is formed on the wafer.

Abstract: There is disclosed aberration measuring method of a projection optical system comprising collectively irradiating the finite region of the photomask in which a diffraction grating is formed with the illuminating light emitted from secondary light source having point sources, projecting 0th-order and 1st-order diffracted lights to first and second measurement planes conjugated with the secondary light source by using a projection optical system, respectively, the 0th-order and 1st-order diffracted lights being passed through the photomask, measuring a relation of projected positions in the first and second measurement planes between the 0th-order diffracted light and 1st-order diffracted light of the light emitted from one arbitrary point source, respectively, obtaining lay aberration concerning the light emitted from the point source on the basis of the obtained two relations of projected positions.

Abstract: The invention provides an automatic lens meter comprising an optical system forming a pattern image by projecting a pattern created by a pattern creating member and measuring optical properties of a lens based on the displacement of the pattern image from a baseline position wherein the examined lens is not in the path of rays in the optical system to a measuring position wherein the examined lens is in the path of the rays. The lens meter includes an image sensor for detecting the position of the pattern image using four line sensors 10a, 10b, 10c and 10d disposed on a pattern image forming plane and arranged in a cross shape, and the pattern creating member forms a pattern image having a quadrangular shape on the pattern image forming plane so that each line sensor intersects a side of the quadrangle, thereby facilitating accurate measurement of desired optical properties.

Abstract: A device for measurement of the spectral reflectance of a surface where the reflectance factor of light with a certain wavelength can be measured in a wide wavelength range, including the UV range, and in which a reference reflectance factor can be easily obtained. The device for measurement has a light source part with a xenon lamp; a fiber on the incidence side; a measurement head which emits the light transmitted by the fiber via a convergent lens and a diffuser onto the surface of the measuring object and which receives the light reflected by the surface; a fiber on the exit side; and a spectroradiometer which receives the light which has been transmitted by the fiber on the exit side.

Abstract: A system is provided for producing a high contrast image of features of an optical component. In the system of the present invention, light is focused through the optical component prior to reaching the detector of an image sensing means. In addition, a novel cuvette is provided for holding and locating an optical component in position during inspection. The cuvette comprises a bottom portion having a concave curved inner surface for utilizing the force of gravity to hold an optical component in place.

Abstract: A method (and system) for manufacturing an optical switching device. The method includes forming an array plate comprising at least one hundred sites from a first physical process, where each of the sites is for coupling to an optical fiber. The sites have a first spatial degree of error relative to an ideal mathematical grid of the sites. The first spatial degree of error is derived from at least the first physical process. The method forms a lens plate comprising a plurality of lenses from a second physical process. Each of the lenses is going to be coupled to at least one of the sites on the array plate. The lenses have a second spatial degree of error relative to a second mathematical grid of lenses. The second spatial degree of error is derived from at least the second physical process. The method then derives lens measurement values from each of the plurality of lenses.

Abstract: The present invention discloses a diffractive optical element whose optical axis can be precisely positioned, and a method of manufacturing the diffractive optical element. The diffractive optical element includes a region provided with a concentric uneven pattern and having a predetermined light bending characteristic, and a peripheral section worked so that the optical axis of the diffractive optical element determined by the light bending characteristic of the region aligns with the center of the profile of the diffractive optical element.

Abstract: An apparatus for inspecting a collimator including a pigtail formed with first and second fibers, a GRIN lens disposed coaxially relative to the pigtail, and a glass tube supporting the pigtail and the GRIN lens in a single unit, to inspect optical properties of the collimator, comprising an inspection table; a gripping part, which is provided on the inspection table, gripping the collimator subject to inspection; a light supplying part transmitting a predetermined optical signal to the first fiber; a light receiving part, which is connected to the second fiber, receiving an optical signal returned from the second fiber, entering the first fiber; a measuring part calculating a value of the predetermined optical signal, which entered the first fiber, and a value of the optical signal, which returned from the second fiber; and an image displaying part displaying the value obtained from the measuring part.

Abstract: An aberration mark for use in an optical photolithography system, and a method for estimating overlay errors and optical aberrations. The aberration mark includes an inner polygon pattern and an outer polygon pattern, wherein each of the inner and outer polygon patterns include a center, and two sets of lines and spaces having a different feature size and pitch that surround the outer polygon pattern. The aberration mark can be used to estimate overlay errors and optical aberrations. In some embodiments, the mark can also be used with scatterometry or scanning electron microscope devices. In other embodiments, the mark can be used to monitor aberrations of a lens in an optical photolithography system.

Abstract: The present invention provides a method and apparatus for automatically and continuously conducting the layout analysis, the blocking (attachment) of an uncut lens to a lens holder, and the process of grinding an edge of three types of lenses, such as a single-vision lens, a progressing multifocal lens and a multifocal lens, utilizing a calculated approximation of the optical center of the uncut lens and by determining the position to which a lens holder should attach to the uncut lens.

Abstract: an apparatus for inspecting a collimator including a pigtail to which a fiber is connected to transmit an optical signal, a GRIN lens coaxially arranged with the pigtail, a glass tube accommodating and supporting the pigtail and the GRIN lens, and a metal sleeve protecting the glass tube, comprising an inspection table; a grip part provided on the inspection table, and gripping the collimator to be inspected; a first camera provided over the grip part having an axis perpendicular to a length of the collimator, and photographing the collimator along the length of the collimator; a second camera arranged coaxially with the collimator on the inspection table, and photographing the collimator perpendicular to an axis of the collimator; and a displaying part connected to the first and second camera, and displaying pictures transmitted from the first and second cameras.

Abstract: In an inspection module for inspecting optical parts (12) for defects, especially contact lenses manufactured as injection-moulded parts, the optical parts (12) are illuminated from one side and are observed from the opposite side by means of an image-resolving sensor (34). The image data of the sensor (34) are forwarded to image-processing means for identification of defects. To obtain a high throughput with a simple construction, a chain (52) of liquid-filled vessels (10) circulating in an endless line is provided. The endless line is passed in an inspection station (72) between an illumination device (32) and the image-resolving sensor (34). Handling means in the form of grippers (56, 58) revolve with the vessels (10), by means of which optical parts (12) to be inspected can be introduced into the vessels (10) at a position of the line upstream of the inspection station (72) and the inspected parts can be taken out of the vessels (10) at another position of the line.

Abstract: Methods for determination of parameters in lithographic devices and applications by diffraction signature difference analysis, including determination of center of focus in lithography devices and applications. Latent image analysis may be employed with exposed but undeveloped lithographic substrates. Control methods are provided for process control of center of focus in lithography devices utilizing diffraction signature difference analysis.

Abstract: Methods and reticles for evaluating lenses are disclosed. In one instance, a reticle which permits light to pass therethrough is provided which includes a first surface with a grating profile formed thereon. The grating profile includes a plurality of grouped stepped portions. Each group of the stepped portions includes a first step which prevents light from propagating therethrough, a second step which propagates light therethrough and a third step which propagates light therethrough at an angle 60 degrees out of phase with the light propagated through the second step.

Abstract: A system for determining response characteristics, insertion loss and group delay, of an optical component by applying a sweeping wavelength optical signal that is modulated with an RF signal, measuring the insertion loss and group delay at a series of wavelengths and correlating the measurements to wavelengths. A method for synthesis of an effective modulation frequency in determining the group delay response characteristics of an optical component by obtaining a series of measurements over a sample optical spectrum using a given modulation frequency and calculating a weighted average of the group delays in the series of measurements giving a result substantially equivalent to a measurement taken using a modulation frequency equal to the effective modulation frequency.

Abstract: A method for analyzing gaseous or liquid samples is provided. Samples are interacted with pores of a porous thin film. A time-varying response of reflectivity is obtained from the surface of the porous thin film during the interaction. One or more analytes forming the sample or a part of the sample are identified based upon the time-varying response.

Abstract: A laser beam emitted from a laser source is split by a beam-splitting means such as a beam sampler, and the power Q of the split beam is measured by a first detector. In addition, the power q1 of light that has passed through a pinhole while a DOE is not set is measured by a second detector, and the power ratio &agr;=q1/Q is calculated. Then, the DOE is set and the power ratio &bgr;k=qk/Q, where qk is the power of each light beam, is calculated. The power ratio &bgr;k is evaluated on the basis of the power ratio &agr;, so the optical properties of a diffractive optical element, in particular, in terms of diffraction efficiency in laser-beam diffraction and intensity uniformity of split beams can be measured with high accuracy.

Abstract: An object pattern is imaged by an imaging system onto the image plane of the imaging system at a location where a reference pattern suited to the object pattern is situated in order to measure the imaging fidelity of an optical imaging system, for example, an eyeglass lens, a photographic lens, or a projection lens, for use in the visible spectral range. The resultant, two-dimensional, superposition pattern is detected in a spatially resolved manner in order to determine imaging parameters therefrom. The object pattern is generated with the aid of at least one electronically controllable pattern generator that serves as a self-luminous, electronically configurable, incoherent light source and may, for example, have a color monitor. The measuring system allows rapidly, flexibly, checking optical imaging systems with minimal time and effort spent on the mechanical setup required.

Abstract: A system and method for real time process control, using a linearly swept tunable laser, which allows high speed in-situ monitoring and control of wavelength-specific properties of optical components. The invention comprises scanning an optical component with a high speed, high linearity tunable laser, and detecting optical output from the component during the scanning. Preferably, the invention also includes adjusting or controlling the optical properties of the component during scanning, according to detected optical output from the component. The invention is embodied in a process control system comprising a high speed, high linearity, tunable operatively coupled to an optical component which in turn is operatively coupled to an optical detector. A system control processor is operatively coupled to the tunable laser and detector. A processing control unit is associated with the optical component and is operatively coupled to the system control processor.

Abstract: An aberration detector for easily detecting aberration of a lens in a short time period by utilizing an interferometer. The aberration detector includes a laser diode, a beam splitter for dividing a light beam into two light beams, an optical system for supporting a lens and converging a light beam passing through the lens to a converging point, a spherical mirror for reflecting the light beam passing through the lens, an image pickup element for detecting an interference pattern obtained by interference of a reference light and the light reflected on the spherical mirror, and an analyzer for analyzing the interference pattern. A center of a sphere constituting the spherical mirror is arranged in a position displaced from the converging point such that a plurality of circular fringes are concentrically arranged on the interference pattern.

Abstract: A reticle (16) having a test pattern (TP) for measurement of an optical characteristic of a projection optical system (17) has a pattern adapted so that a high frequency component of a spectrum at a pupil plane (18) of the projection optical system (17) is reduced or suppressed. Illumination light is projected to the test pattern of the reticle (16) in one direction or plural directions, and positions of images of the test pattern (TP), formed by the projections in the plural directions, are detected and, based on it, the optical characteristic of the projection optical system (17) is measured.

Abstract: The present invention relates to an apparatus for measuring a slant angle in a solid immersion lens. In a near-field optical data storage head for storing/reading data using a solid immersion lens (SIL), a parallel light is formed within the plane of the solid immersion lens and the slant angle of the parallel light is then measured using the angle measurement principle of the autocollimator in order to measure the slant angle of the solid immersion lens. For this, the present invention includes an optical system for generating the parallel light within the solid immersion lens, and a unit for measuring the slant angle of the solid immersion lens using a location detection unit. An incident light becomes the parallel light by the optical system and the curved face of the solid immersion lens. The reflected light is also focused on the location detection unit. The location detection unit converts the reflection angle of the reflecting light into a location value to calculate the angle value.

Abstract: A method is described for determining lens aberrations using a test reticle and a standard metrology tool. The method provides test patterns, preferably in the form of standard overlay metrology test patterns, that include blazed gratings having orientation and pitch selected to sample desired portions of the lens pupil. The method measures relative shifts in the imaged test patterns using standard metrology tools to provide both magnitude and sign of the aberrations. The metrology tools need not be modified if standard test patterns are used, but can be adapted to obtain additional information. The test reticles may be formed with multiple test patterns having a range of orientations and pitch in order to compute any desired order of lens aberration. Alternatively, single test patterns may be used to determine both the magnitude and sign of lower order lens aberrations, such as defocus or coma.

Abstract: A method for testing a material block prior to forming the material block into one or more optical components for use with a sub-micron lithographic, high power, narrow bandwidth laser system having high wavelength stability includes the step of selecting a block of material having appropriate characteristic optical properties for the source laser system being used. The next step is to test the material block for absorption performance. Then, if the block exhibits a sufficient absorption performance, then one of more optical components such as one or more prisms, etalons, and/or windows, etc. are formed from the material block. Finally, the optical components formed from the block are inserted into a wavelength selection module of the resonator of the laser to participate in producing a high power, narrow bandwidth laser beam which may be used in sub-micron photolithographic applications.

Abstract: The invention provides an apparatus and a method for measuring the geometrical structure of an optical component (2) in transmission, comprising the steps:

Abstract: A method and system for inspecting ophthalmic lenses using absorption where an ophthalmic lens is illuminated with light comprising wavelengths that are substantially absorptive to said lens, the image subsequently detected being created using only light at said absorptive wavelengths. Variations in transmitted light intensity translate into thickness changes in the lens caused by cosmetic flaws. The invention is also directed to imaging lens assemblies employing highly positive-powered field flattening lens elements to image a curved object, such as an ophthalmic lens, onto a flat image plane.

Abstract: An assembly and method for inspecting ophthalmic lenses includes a light source and a 360° light structuring aperture configured to direct structured light toward an open center where a lens is positioned for imaging by an imaging device positioned beneath the assembly. The structured light is directed at the entire periphery of the lens and is internally reflected by the lens in the manner of a fiber optic conduit whereby the lens appears dark at clear areas of the lens. If there are defects or imprints on the lens, the internally reflected light will scatter at that point and appear as a bright spot to the imaging device.

Abstract: A projection lens distortion error map is created using standard overlay targets and a special numerical algorithm. A reticle including a 2-dimensional array of standard overlay targets is exposed several times onto a photoresist coated silicon wafer using a photolithographic stepper. After exposure, the overlay targets are measured for placement error using a conventional overlay metrology tool. The resulting overlay error data is then supplied to a software program that generates a lens distortion error map for the photolithographic projection system.

Abstract: A method of detecting aberrations associated with a projection lens utilized in an optical lithography system. The method includes the steps of forming a mask for transferring a lithographic pattern onto a substrate, forming a plurality of non-resolvable features disposed on the mask, where the plurality of non-resolvable features are arranged so as to form a predetermined pattern on the substrate, exposing the mask using an optical exposure tool so as to print the mask on the substrate, and analyzing the position of the predetermined pattern formed on the substrate and the position of the plurality of non-resolvable features disposed on the mask so as to determine if there is an aberration. If the position of the predetermined pattern formed on the substrate differs from an expected position, which is determined from the position of the plurality of non-resolvable features, this shift from the expected position indicates the presence of an aberration.

Abstract: A method of evaluating an imaging performance of an imaging optical system includes providing a member having a measurement mark with a predetermined surface level difference, illuminating the member having the measurement mark through the imaging optical system, and receiving reflection light from the illuminated measurement mark again through the imaging optical system. A detection signal is produced based on the measurement mark, illuminated through the imaging optical system, wherein the detection signal is produced while changing a focus within a depth of focus of the imaging optical system. A positional deviation is measured on the basis of the detection signal, and the imaging performance is evaluated of the imaging optical system on the basis of a change in a measured value of the positional deviation measurement with respect to a change in the focus.

Abstract: An inspection tool or inspection system can be utilized to determine whether the appropriate pattern is on a reticle. The reticle can be associated with EUV lithographic tools. The system utilizes an at least two wavelengths of light. The light is directed to the reticle at the at least two wavelengths of light.

Abstract: A laser system is disclosed wherein a tunable laser signal has encoded within it information related to its wavelength at any instant in time. This encoding in one example is performed by modulating the signal to contain its wavelength information. This is particularly useful in a distributed system for testing optical components, wherein at a test site, the test station must determine the wavelength of light at which a component was tested.