Embodiments of the invention provide a method of determining one or more characteristics of a target object, comprising recording one or more diffraction patterns at a detector, wherein each diffraction pattern is formed by a target object scattering incident radiation, determining a phase map for at least a region of the target object based on the one or more diffraction patterns, and determining a refractive property of the target object based on the phase map.

A measurement apparatus for a surface shape of a highly reflective mirror, comprising a light source, a beam splitting sheet, a collimator, a standard mirror plated with the beam splitter sheet, and a CCD imaging system. A light beam emitted by the light source passes through the beam splitting sheet, and is converted by the collimator into parallel light lo which passes through the standard mirror, a part of the light is reflected and returned by the standard mirror, and the other part of light passes through the standard mirror, and then reaches the surface of a measured mirror and is reflected back by the surface; the light IR reflected back by the standard mirror and the light It reflected back by the surface, pass through the standard mirror, forming interfering light that is returned to and reflected by the beam splitting sheet before entering the CCD imaging system.

With regard to an eyeglass lens that is provided with a plurality of defocus regions on at least one of an object-side surface and an eyeball-side surface, the surface shape is evaluated through measuring the surface shape of the surface of the eyeglass lens that has the plurality of defocus regions, and acquiring three-dimensional data regarding the surface shape; a classifying data groups regarding the plurality of respective defocus regions and a data group regarding a base region, which is a region where the defocus regions are not formed, by performing cluster analysis on the three-dimensional data; combining curved surface shape data obtained by performing curve fitting on each of the classified data groups, and extracting reference shape data regarding the object-side surface; and comparing the three-dimensional data and the reference shape data, and obtaining degrees of deviation of the three-dimensional data from the reference shape data.

An optical coherence tomography (OCT) measurement system for precision measurement of a translucent sample is provided. The system includes an optical coherence tomography (OCT) imaging system comprising a broadband light source, a reference path with reference path length, and sample path with a beam scanning assembly and an imaging lens assembly; a sample positioning assembly including an immersion bath for positioning the translucent sample within an immersion bath; a position assembly for locating the translucent sample within a field of view (FOV) of the OCT imaging system; an immersion lens assembly associated with the imaging lens assembly configured to eliminate an air to bath refractive interface between a distal surface of the OCT imaging lens including an immersion tip and a surface of the bath; a first set of calibration parameters that relate a position of a scanning beam at an imaging plane to drive signals of the scanning assembly; and a second set of calibration parameters for relating an optical path length or optical path length variation of the scanning beam at an imaging plane to the position of the scanning beam or to the drive signals of the scanning assembly.

A method for determining geometrical parameters of a soft contact lens comprises the steps of providing an OCT imaging device comprising an OCT light source; providing a soft contact lens arranging the soft contact lens relative to the OCT imaging device so light coming from the OCT light source impinges on the back surface of the soft contact lens; generating a three-dimensional OCT image of the soft contact lens; from the three-dimensional OCT image determining a plurality of edge points located on the edge of the soft contact lens, connecting adjacent ones of the edge points by individual straight lines; summing up the lengths of all individual straight lines to a length U of the approximated circumference of the soft contact lens; from the length U determining a diameter D of the lens according to D=U/π.

A shape measuring apparatus applies, to a light beam, a periodic pattern having periodicity in a direction perpendicular to an optical axis and displaceable in the direction perpendicular to the optical axis, relatively displaces a focal point of an objective lens in a direction parallel to the optical axis, and calculates, based on amplitude of intensity of the light beam detected by a photodetector, face shape data on the object to be measured. Then, a top surface measuring step of acquiring face shape data on a top surface of the object to be measured, and a bottom surface measuring step of acquiring face shape data on a bottom surface of the object to be measured by transmitting through the top surface of the object to be measured and aligning the focal point of the objective lens on the bottom surface of the object to be measured are performed.

A method and system for identifying a given geometrical feature of an optical component or semi-finished ophthalmic lens blank, where an optical component is made of an organic material that can emit light at an emission wavelength λ.sub.e when being lighten at an illumination wavelength λ.sub.i different from the emission wavelength λ.sub.e, a surface of the optical component is illuminated with an incident light beam including at least light at the illumination wavelength but devoid from light at the emission wavelength, light emitted at the emission wavelength by the illuminated surface is collected to build an image of the surface, and the surface image is processed to apply metrics to compare the image with reference data specific to the given geometrical feature.

Disclosed is a stitching-measurement device adapted for performing stitching-measurement on a surface of a concave spherical lens, including: an interferometer, a reference lens, a first plane mirror, a second plane mirror, a first adjustment mechanism, a second adjustment mechanism, a concave spherical object to be measured, a motion table and a control mechanism, the first plane mirror being mounted on the first adjustment mechanism configured to change a position of the first plane mirror; the second plane mirror being mounted on the second adjustment mechanism configured to change a position of the second plane mirror; the concave spherical object to be measured being placed on the motion table configured to change a position of the concave spherical object to be measured; the control mechanism communicating with the interferometer, the first adjustment mechanism, the second adjustment mechanism, and the motion table for issuing control signals, wherein by the first adjustment mechanism and the second adjustment mechanism, an included angle between the first plane mirror and the second plane mirror is adjusted in such a way that light beam incident on the concave spherical object to be measured is inclined by a first angle relative to light beam emitted from the reference lens, thereby avoiding an operation of inclining the concave spherical object to be measured during the stitching-measurement.

A diffractive optical element (10) for a test interferometer (100) measures a shape of an optical surface (102). Diffractive shape measuring structures (16) are arranged on a used surface (14) of the element and generate a test wave (122) irradiating the surface when the element is arranged in the interferometer. At least one test field (18) several profile properties of test structures contained in the test field. The profile properties characterize a profile line of the test structures extending transversely with respect to the used surface and include a flank angle of the profile line, a profile depth and a depth of a microtrench in a bottom region of a trench-shaped profile of the test structures. The test field is arranged at one location of the used surface instead of the diffractive shape measuring structures such that the test field is surrounded by several diffractive shape measuring structures.

A corrected optical lens includes an inner layer that includes a low stress optical lens and an outer layer that includes one or more corrective layers. The outer layer may be formed on at least a portion of an outer surface of the inner layer by scanning the outer surface of the inner layer, generating a surface characterization file based on the outer surface scan, and 3D printing the one or more corrective layers on the outer surface of the inner layer based on the surface characterization file as input to a 3D printer. The surface characterization file may be corrected based on a particular predetermined contour of the inner layer prior to being input to the 3D printer. The correction may include, for example, reduction of root mean square (RMS) values of deviations of detected peaks and valleys on the surface of the inner layer.