A simultaneous phase-shift point diffraction interferometer and method for detecting wave aberration. The interferometer comprises an ideal spherical wave generation module, an optical system to be measured, an image plane mask, a polarization phase shift module, a two-dimensional polarization imaging photodetector and a data processing unit. Single photodetector is adopted to realize simultaneous detection of more than three phase shift interference patterns, and has the advantages that environmental interference suppression, a flexible optical path, high measurement accuracy, and calibration of system errors of the interferometer may be realized.

A test appliance and a method for testing a mirror, e.g., a mirror of a microlithographic projection exposure apparatus. The test appliance has a computer-generated hologram (CGH), and a test can be carried out on at least a portion of the mirror by way of an interferometric superposition of a test wave that is directed onto the mirror by this computer-generated hologram and a reference wave. Here, the computer-generated hologram (CGH) (120, 320) is designed in such a way that, during operation of the appliance, it provides a first test wave for testing a first portion of the mirror (101, 301) by interferometric superposition with a reference wave in a first position of the mirror (101, 301) and at least a second test wave for testing a second portion of the mirror (101, 301) by interferometric superposition with a reference wave in a second position of the mirror (101, 301).

Generating a composite image of a non-flat surface includes: acquiring, using a microscope, multiple images of different areas of the non-flat surface, where each image includes a region of overlap with at least one adjacent image, the microscope having sufficient resolution to image in three dimensions a microstructure on the non-flat surface having a lateral dimension of 10 microns or less and a height of 10 nm or less; determining, for each of the images, a set of rigid body parameters relating a position and orientation of the test object in the image to a common coordinate system, where the set of rigid body parameters is determined by fitting the resolved microstructure in the overlap region in the image with the corresponding microstructure in the overlap region of the adjacent image; and combining the images based on the sets of rigid body parameters to generate a composite image.

Apparatus and method for detecting wavefront aberration of an objective lens, comprising a wavefront detection system, a planar mirror, and a planar mirror adjusting mechanism; the objective lens is placed between planar mirror and wavefront detection system; planar mirror is positioned at focal point of the objective lens. A test wavefront emitted by wavefront detection system passes through the objective lens, gets reflected by the planar mirror, and t passes through the objective lens again; the wavefront detection system receives and detects the test wavefront to derive a phase distribution thereof; an angle of the planar mirror tilts at is adjusted to obtain different return wavefronts; a polynomial for expressing wavefront aberration is selected, and expressions corresponding to all the return wavefronts are calculated; result of fitting the wavefront aberration of the objective lens when expressed by the selected polynomial is derived through fitting with the polynomial.

A system for measuring the topography of a surface including a carriage assembly and a base assembly. The carriage assembly comprising a plurality of displacement-measuring probes coupled to a carriage support structure. The base assembly positioned adjacent to the carriage assembly and comprising at least one reference object with an opening sized to receive a test object. At least one of the carriage assembly or the base assembly is configured to translate with respect to the other in at least two directions to enable at least one of the displacement-measuring probes to measure a displacement to a reference surface of the reference object and at least another one of the displacement-measuring probes to measure a displacement to a target surface of the target object whose topography is measured.

A method for analyzing the wavefront effect of an optical system includes: illuminating a measurement mask (110, 310) with illumination light, producing an interferogram in a specified plane using a diffraction grating (150) from a wavefront from the illuminated measurement mask and traveling through the optical system; and capturing the interferogram with a detector (170). Different angular distributions of the illumination light incident on the measurement mask are produced via a mirror arrangement of independently settable mirror elements. A plurality of interferograms are captured in a plurality of measurement steps, wherein these measurement steps differ respectively in angular distribution of the illumination light that is incident on the measurement mask. A matching wavefront deviation portion in the measurement results obtained respectively in the measurement steps is ascertained to determine the respective system wavefront deviations of the optical system for the pupil regions illuminated respectively in the individual measurement steps.

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.

Methods and mechanisms for correcting a wavefront error in an optical element are disclosed. A wavefront error that is downstream of an optical element in an optical path is determined. A refractive index prescription that reduces the wavefront error is determined. A beam of energy is directed at a surface of the optical element in accordance with the refractive index prescription to alter the surface to change an index of refraction at multiple locations on the surface.

A detection device adapted to detect lens surface and a stitching interferometer including the same are disclosed. The detection device includes: a cylindrical detection frame comprising support bosses arranged on an inner wall of the detection frame in a circumferential direction of the detection frame, the lens to be detected being placed on the support bosses; and a plurality of support units mounted at a bottom of the detection frame in the circumferential direction of the detection frame, each of the support units comprising: a support mechanism configured to be movable in an axial direction of the detection frame and cooperate with the support bosses so as to support the lens to be detected together; and a balance mechanism configured to provide a balancing force for balancing with force of the support mechanism for supporting the lens to be detected, so that axial support force of each supporting unit for the lens to be detected is equal to axial support force of each support boss for the lens to be detected in both cases where the axial direction of the detection frame is parallel to a gravity direction of the lens to be detected and inclined with respect to the gravity direction of the lens to be detected.