Method for measuring a spherical-astigmatic optical surface (40), includes: a) generating a spherical-astigmatic wavefront as a test wavefront with a wavefront generating apparatus (10); b) interferometrically measuring wavefront aberrations between the wavefront generating apparatus and the surface which is adjusted to the wavefront generating apparatus such that the test wavefront impinges each point on the surface substantially perpendicularly, plural measurements being taken in which the surface is measured at a number of positions, spherized about the two centers of the radii of the astigmatism and/or rotated by 180 about a surface normal to the surface, such that corresponding interferogram phases are determined; and c) determining the wavefront of the wavefront generation device and a shape of the surface using a mathematical reconstruction method. The spherical-astigmatic surface is then corrected using a suitable processing method, a) to c) being repeated until the wavefront aberrations are smaller than a given value.

Determining an imaging aberration contribution of an imaging optical unit for measuring lithography masks involves firstly focus-dependently measuring a 3D aerial image of the imaging optical unit as a sequence of 2D intensity distributions in different measurement planes in the region of and parallel to an image plane of an imaging of an object by use of the imaging optical unit. A spectrum of a speckle pattern of the 3D aerial image is then determined by Fourier transformation of the measured 2D intensity distributions having speckle patterns. For a plurality of spectral components in the frequency domain, a focus dependence of a real part RS(z) and an imaginary part IS(z) of said spectral component is then determined. From the determined values of the focus dependence of the real part RS(z) and the imaginary part IS(z), a contribution made to the speckle pattern spectrum by a mask structure, which contribution is to be eliminated, is then separated from an imaging aberration contribution made to the speckle pattern spectrum by the imaging optical unit. The imaging aberration contribution is then represented. This results in a method for determining the imaging aberration contribution of the imaging optical unit having little additional time expenditure in comparison with the measurement time on the respective lithography mask.

A multi-wavelength wavefront system and method for measuring diffractive lenses. A system may include one or more light sources configured to emit a plurality of wavelengths of light for diffraction by a diffractive lens. A light sensor may be configured to receive the light that is diffracted by the diffractive intraocular lens. A processor may be configured to determine one or more of the plurality of wavelengths that have a peak diffraction efficiency for the diffractive intraocular lens based on the light received by the light sensor.

A method for assessing the similarity between a power profile of a manufactured optic device and a nominal power profile upon which the power profile of the manufactured optic device is based. The method comprises measuring the power profile of manufactured optic device, identifying a region of interest from the measured power profile of manufactured optic device, and applying an offset to the measured power profile to substantially minimize a statistical quantifier for quantifying the similarity between the nominal power profile and the offset measured power profile. The method further comprises comparing the offset and the statistical quantifier to predefined quality control metrics, determining whether the measured power profile meets the predefined quality control metrics based, at least in part on the comparison. In exemplary embodiments, the method may further comprise determining whether to associate the manufactured optic device with another nominal power profile, if the measured power profile does not meet the predefined quality control metrics.

Optical binocular disparity detection devices may include an optical combiner and a single image sensor. The optical combiner may include a left input for receiving a left image and a right input for receiving a right image. An output of the optical combiner may be configured to direct the left image and the right image out of the optical combiner. The single image sensor may be configured to receive and sense the left image and the right image from the output and to generate data indicative of a disparity between the left image and the right image. Various other related systems and methods are also disclosed.

A two-dimensional diffraction grating for a phase-stepping measurement system for determining an aberration map for a projection system comprises a substrate provided with a square array of through-apertures, wherein the diffraction grating is self-supporting. It will be appreciated that for a substrate provided with a square array of through-apertures to be self-supporting at least some substrate material is provided between each through-aperture and the adjacent through apertures. A method of designing a two-dimensional diffraction grating for a phase-stepping measurement system for determining an aberration map for a projection system comprises: selecting a general geometry for the two-dimensional diffraction grating, the general geometry having at least one parameter; and selecting values for the least one parameter that result in a grating efficiency map for the two-dimensional diffraction grating so as to control the contributions to a first harmonic of a phase stepping signal.

An object of the present invention is to provide an optical fiber test method, an optical fiber test apparatus, and a program, capable of detecting a boundary of an optical fiber line facility regardless of a change in a noise amount. A change amount (a differential value) of an OTDR waveform increases toward a distal end due to noise effects, making it difficult to determine a boundary of the optical fiber using the change amount. Therefore, in the present invention, a dispersion of the OTDR waveform, which increases toward a distal end due to noise effects, is also used to determine the boundary of the optical fiber. In other words, in the present invention, the noise amount is expressed by the dispersion, and the dispersion is compared with the change amount such as a differential value as a threshold, to determine the boundary of the optical fiber. For this reason, when noise increases, the threshold increases together with an increase in the change amount, and therefore, the boundary of the optical fiber can be determined regardless of noise.

A method for qualitatively detecting aberration and determine aberration types in a photolithography system is disclosed. The method includes using a digital micromirror device (DMD) pattern to project an optical signal on a reflective substrate, acquiring a return optical signal reflected from the substrate at different focus heights (ranging from above to below best focus), forming a through focus curve based off of the return optical signal at various focus heights, comparing the through focus curve to a predetermined curvethe predetermined curve being a function of focus, and determining if a lens aberration is present. By using the existing hardware of the photolithography system to determine if a lens aberration exists, costs are maintained at a minimum and the DMD pattern creates a through focus curve (TFC) image in less than five minutes allowing for quick correction.

The present disclosure illustrates a non-contact measurement device for a radius of curvature and a thickness of a lens and a measurement method thereof. The non-contact measurement device utilizes a non-contact probe to integrate a motor, an optical scale and an electronic control module, so as to achieve measurement for the radius of curvature and the thickness of the lens. The present disclosure adopts astigmatism to achieve fast and precise focusing. To overcome the spherical aberration problem, thickness measurement can be implemented by the non-contact measurement device through a formula calculation and utilization of a correction plate, wherein single one probe is used for the measurement herein. For the thicker lens, the non-contact measurement device can be extended to use dual probes, so as to detect the top and bottom sides of the lens.

A system for detecting refractive power of a dry ophthalmic lens under inspection, comprising: a) a top camera 10 arranged to view the ophthalmic lens 40 through an optical module 25; b) an optically transparent surface 30 to position the ophthalmic lens 40 for inspection; c) a precisely calibrated glass target 50 suitably positioned on a transparent plate 60, arranged to achieve an image of the ophthalmic lens 40 overlaid with the image of the pattern on the target 50; d) at least one light source having multiple wavelength LEDs to capture different images under multiple lighting conditions.