51 results about "Phase shifting interferometry" patented technology

An in vivo method of characterizing dynamic tear films has been developed using a near infrared phase-shifting interferometer. This interferometer continuously measures light reflected from the tear film, allowing precision analysis of the dynamic surface topography. Movies showing the tear film behavior may be generated along with quantitative metrics describing the tear film surface as it changes in time.

Device and method for wavefront measurement of an optical imaging system by means of phase-shifting interferometry, having a mask structure (6a) to be arranged on the object side, and / or a grating structure (7a) to be arranged on the image side. The object-side mask structure includes one or more one-dimensional mask structure patterns, and the image-side grating structure includes one or more two-dimensional grating structure patterns. Alternatively, conversely, the mask structure includes one or more two-dimensional patterns, and the grating structure includes one or more one-dimensional patterns. Additionally or alternatively, a pupil position offset caused by a lateral relative movement of the mask structure and detector element can be taken into account by back calculating the interferogram, respectively recorded by the detector element, using an associated phase-shift characteristic, or by a computational correction of wavefront derivatives, obtained from the recorded interferograms, in the direction of lateral movement. The method and / or the device can by used, for example, for determining aberration in the case of high-resolution projection objectives of microlithography exposure machines using shearing or point interferometry.

The invention relates to a device for detecting a precision wafer based on parallel optical flat splitting polarized beam and phase-shifting interferometry. The device comprises a light source, a spatial filter, a beam expander, a polarizer, a depolarizing dispersion prism, a parallel optical flat, a quarter-wave plate and an analyzer, wherein the light source, the spatial filter, the beam expander and the polarizer are arranged on a first optical axle in sequence, the analyzer, the quarter-wave plate, the depolarizing dispersion prism, the parallel optical flat and the surface of an externalobject to be measured are arranged on a second optical axle in sequence, and the first optical axle is perpendicular to the second optical axle.

The invention relates to a method for analyzing the surface profile of the object to be measured, which relates to a method for obtaining the surface profile of the object to be measured by analyzing the interference intensity, and uses a spectroscopic interferometer combined with a broadband light source (white light) to perform analysis. The analysis method of the present invention combines the vertical scanning interference analysis algorithm and the phase analysis algorithm to describe the surface profile of the object to be measured, and has high measurement resolution. In addition, the analysis method of the present invention can analyze the phase and contour information of the object to be measured with only one piece of interference intensity data. Only in the vertical scanning interferometry mode can the phase and profile information of the object under test be obtained. Therefore, the analysis method of the present invention can further shorten the time required for measurement, and can be applied to the occasion of on-line product quality inspection.

The invention discloses a dual-wavelength phase-shift interference-based method for measuring optical heterogeneity, wherein according to dispersion characteristics of a material, an interferometer which comprises two lasers with different optical wavelengths or a wavelength tunable laser is adopted, and refractive index heterogeneity of a sample to be measured under optical waves of two wavelengths is considered as the same as optical heterogeneity to be measured of the sample to be measured; a phase-shift interferogram of the sample to be measured under the optical waves of the two wavelengths before being put into the interferometer, and a phase-shift interferogram of the sample to be measured under the optical waves of the two wavelengths after being put into the interferometer are obtained by using phase-shifting interferometry;and physical light wave phase difference of the sample to be measured under the optical waves of the two wavelengths before / after being put into the interferometer is obtained by using a phase-shift interference phase recovery algorithm, and then the optical heterogeneity of the sample to be measured is obtained. According to the dual-wavelength phase-shift interference-based method for measuring the optical heterogeneity, system errors are automatically eliminated, the sample to be measured does not need to be adjusted during a process of measuring, no special requirements for surface shape, parallelism and machining accuracy of a front and a rear surfaces of the sample to be measured exist, thus the dual-wavelength phase-shift interference-based method for measuring the optical heterogeneity is a genuine absolute measuring method and has high measuring accuracy.

The invention discloses an interferometric phase microscopy one-step imaging system and method based on two-step phase shift, and adopts the technical scheme that based on a typical Mach-Zehnder interference light path, lateral displacement beam splitting mirrors are adopted to perform light splitting on sample light and reference light respectively, a wave plate is utilized as a phase shifter, and two interference figures can be acquired at the same time through single exposure, and phase imaging can be realized quickly through corresponding phase recovery operation, and a spatial form structure of a phase body is further deconstructed. The interferometric phase microscopy one-step imaging system and method are suitable for all interferometric phase microscopy imaging systems, such as traditional coaxial interference, off-axis interference and slight off-axis interference, and have high practical value and wide application prospect in the aspect of phase microscopy, particularly in the field of application and identification of biological cell morphology.

The invention discloses a single-black-and-white CCD phase-shift dual-wavelength interferometric method based on a specific phase shift amount, which includes step 1: constructing a co-path coaxial dual-wavelength interference system, and injecting lasers with two wavelengths of wavelength λ1 and λ2 into the interferometric In the system, adjust the lasers with two wavelengths to form an interferogram along the exact same path; second: adjust the parameters of a single black and white CCD to simultaneously collect two wavelengths of the interferogram; third: use a single black and white CCD to collect the dual waves generated by two wavelengths at the same time Long phase-shift interferogram; 4: From the collected dual-wavelength phase-shift interferogram, separate two sets of single-wavelength phase-shift interference signal images that eliminate the background; 5: Separate two sets of single-wavelength phase-shift interference signal images Carry out normalization processing; Sixth: Calculate the single-wavelength package phase diagram under the wavelengths λ1 and λ2, Seventh: Calculate the synthetic wavelength phase of the wavelengths λ1 and λ2, so as to obtain the surface three-dimensional topography information of the object to be measured. The method is simple and easy to implement.

The invention discloses a secondary confocal measurement method and device based on phase-shifting interference. In the device, a laser emits a linearly polarized beam, which becomes an approximate ideal plane wave after passing through a collimating beam expander group; After one-half of the wave plate, it becomes a circularly polarized beam; it is divided into two beams by the beam splitter, the first beam is transmitted by the beam splitter, reflected by the mirror, reflected by the beam splitter, and converged by the second pinhole and detected by the collecting objective lens. A point detector composed of detectors; the second beam of light is reflected by the beam splitter, converges on the measurement surface through the detection focusing objective lens and the beam splitter, is reflected on the measurement surface, passes through the detection focusing objective lens, and converges on the point detector through the collecting objective lens; the first The micro-driver is used to drive the mirror to change the phase difference between the reference light and the measurement light to realize phase-shifting interference; the initial position of the measurement point is the first confocal state. The invention also discloses a secondary confocal measurement method based on phase-shifting interference.