The spatial structure of an optical element is determined. The optical element has a first optically active surface and a second optically active surface. The optical element is arranged in a holding device. The position of a point (P) on the first optically active surface and the position of a point (P′) on the second optically active surface are referenced in a coordinate system fixed to the holding device. The topography of the first optically active surface is determined in a coordinate system referenced to the holding device by the position of point (P) and the spatial structure of the optical element is calculated from the topography of the first optically active surface and from a data set as to the topography of the second optically active surface. The data set is referenced to the fixed coordinate system of the holding device by the position of point (P′).

A process is provided for determining characteristics of a lens, the process including obtaining a captured image of a pattern through a corrective lens; transforming the captured image to an ideal coordinate system; processing the captured image to determine an overall distortion from a reference pattern to the pattern of the captured image; determining a distortion of the captured pattern attributable to the corrective lens; and measuring at least one characteristic of the corrective lens. In some embodiments, the overall distortion is determined by detecting, in the captured image, at least one captured pattern landmark; determining a transformation from at least one ideal pattern landmark to the at least one captured pattern landmark; and determining for the corrective lens, from the transformation, a spherical power measurement, a cylinder power measurement, and an astigmatism angle measurement.

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.

A lensmeter system may include a mobile device having a camera. The camera may capture a first image of a pattern through a lens that is separate from the camera, while the lens is in contact with a pattern. The mobile device may determine the size of the lens based on the first image and known features of the pattern. The camera may capture a second image of the pattern, while the lens is at an intermediate location between the camera and the pattern. The second image may be transformed to an ideal coordinate system, and processed determine a distortion of the pattern attributable to the lens. The mobile device may measure characteristics of the lens based on the distortion. Characteristics of the lens may include a spherical power, a cylinder power, and/or an astigmatism angle.

A lensmeter system may include a mobile device having a camera. The camera may capture a first image of a pattern through a lens that is separate from the camera, while the lens is in contact with a pattern. The mobile device may determine the size of the lens based on the first image and known features of the pattern. The camera may capture a second image of the pattern, while the lens is at an intermediate location between the camera and the pattern. The second image may be transformed to an ideal coordinate system, and processed determine a distortion of the pattern attributable to the lens. The mobile device may measure characteristics of the lens based on the distortion. Characteristics of the lens may include a spherical power, a cylinder power, and/or an astigmatism angle.

Techniques are disclosed for systems and methods to provide improved ocular aberrometry recovery. An ocular aberrometry system includes a wavefront sensor configured to provide wavefront sensor data associated with an optical target monitored by the ocular aberrometry system and a logic device configured to communicate with the wavefront sensor. The logic device is configured to receive ocular aberrometry output data including at least the wavefront sensor data provided by the wavefront sensor, identify imaging artifact induced singularities in the received ocular aberrometry output data, determine corrected aberrometry output data based, at least in part, on the identified singularities and the received ocular aberrometry output data, and generate user feedback corresponding to the received ocular aberrometry output data based, at least in part, on the corrected aberrometry output data.

A transmissive diffraction grating for a phase-stepping measurement system for determining an aberration map for a projection system comprises an absorbing layer. The diffraction grating is for use with radiation having a first wavelength (for example (EUV radiation). The absorbing layer is provided with a two-dimensional array of through-apertures. The absorbing layer is formed from a material which has a refractive index for the radiation having the first wavelength in the range 0.% to 1.04.

A method for optimization of photonic devices is disclosed. The method includes receiving a set of unconstrained latent variables; mapping the set of unconstrained latent variables to a constrained space to generate a constrained device; calculating the permittivity across each element of the constrained device; determining a permittivity-constrained width gradient based at least partially on the permittivity across each element; and optimizing the set of unconstrained latent variables by at least partially using the permittivity-constrained width gradient.

Disclosed herein is a method including: providing a light guiding arrangement (LGA) configured to redirect light, incident thereon in a direction perpendicular to an external surface of the sample, into or onto the sample, such that light impinges on an internal facet of the sample nominally normally thereto; generating a first incident light beam (LB), directed at the external surface normally thereto, and a second incident LB, parallel to the first incident LB and directed at the LGA; obtaining a first returned LB by reflection of the first incident LB off the external surface, and a second returned LB by redirection by the LGA of the second incident LB into or onto the sample, reflection thereof off the internal facet, and inverse redirection by the LGA; measuring an angular deviation between the returned LBs and deducing therefrom an actual inclination angle of the internal facet relative to the external surface.

A Lens and Camera Testing Method, Apparatus, and System have been disclosed. In one implementation a lens and camera combination is mounted on a gimbal and is tilted at a remote polygon target.