A white light interference three-dimensional shape measurement optical system provided by the present invention comprises a wide spectral coverage light source, a projection illuminating mirror set, aspectroscope, a standard reflector, a first orientation adjuster, a second orientation adjuster, a linear driver, a measurement mirror set and a detector array. The wide spectral coverage light source sends out the wide spectral coverage illumination light, the light is projected to the surface of a measured object and the surface of the standard reflector after passing the projection illuminating mirror set, and the reflection light at two places is combined by the spectroscope to form a spatial interference light field, irradiates to the measurement mirror set and is projected to a photoelectric detector. The white light interference three-dimensional shape measurement optical system of the present invention can image to obtain an interference image carrying the morphology information of a target object, and can real-timely record and observe the interference image of the target object, thereby providing the data bases for obtaining the three-dimensional morphology information and the two-dimensional image information of the measured object.

White light interference three-dimensional shape measurement optical system

For a simultaneous phase-shifting interferometer (SPSI), typically four interferograms with different phase shifts are captured at different areas on the detector target by a single-shot capture method. Prior to calculating phase distribution, the region segmentation should be conducted to obtain four separated interferograms. A registration method is also necessary to eliminate the mismatch errors between the interferograms. A spatial mismatch calibration method based on fast partial phase correlation is proposed to register the spatial positions between the phase-shifting interferograms. By tilting the reflective flat, four carrier interferograms are captured to extract four phase distributions using the Fourier transform technique. Partial phase distribution is used as match characteristics to register the interferograms rapidly by employing the correlation operation. The simulation and experimental results show that the ripple error generated by spatial mismatch is suppressed well by the proposed method.

Spatial mismatch calibration based on fast partial phase correlation for interferograms in dynamic Fizeau interferometer

The invention discloses a point source heterotopic beam expansion synchronous phase shift fizeau interferometer and a measurement method thereof. The interferometer comprises a spot light source array, a fizeau main interferometer and a light splitting imaging assembly. The method comprises steps that four identical spherical waves generated by the point light source array respectively enter the main interferometer, through adjusting a distance between the spot light source array on a collimation object lens focal plane of the main interferometer and a light axis, four collimation wavefronts emitted by the main interferometer are incident to a reference lens in different angles, so different phase shifts are introduced to interference of a reference surface and a test surface, four intelligible imaging phase shift interferograms are simultaneously acquired on a CCD through the light splitting imaging assembly. The interferometer is advantaged in that properties of low cost, good anti-vibration performance and easy operation are realized, and the interferometer can be applied to the real-time high precision detection field of optical elements.

Point source heterotopic beam expansion synchronous phase shift fizeau interferometer and measurement method thereof

A slightly off-axis digital holography is proposed using polarization technology for quantitative phase imaging. Employing a nearly common-path flipping interferometry configuration, our approach realizes interference by flipping the relative position of a sample and reference beam. Using polarization modulation, the sample beam is converted to be 45° linearly polarized, and the reference beam is modulated to be circularly polarized. By setting a polarizer placed before the CCD camera with angles of 0° and 90°, two carrier holograms with phase shifts of 0 and π/2 can be obtained, respectively. Then, the phase distribution of the sample can be retrieved using a fast slightly off-axis digital holography reconstruction method. Theoretical analysis and experiments are carried out to demonstrate the validity and stability of the proposed method.

Slightly off-axis flipping digital holography using polarization technology

The invention discloses a variable-dip-angle phase-shifting mach-zehnder interferometer measuring device and method. The device comprises a light source variable-dip-angle phase-shifting assembly, a main interferometer and an imaging assembly. The parallel light emitted by the light source variable-dip-angle phase-shifting assembly enters the main interferometer, the reference light and the test light in the main interferometer are recombined by a beam splitter prism and then enter the imaging assembly, and an interference pattern is obtained on a CCD target surface. The method comprises the steps that firstly, the light source variable-dip-angle phase-shifting assembly generates collimated light parallel to an optical axis, and a compensation plate is arranged in the main interferometer,the position of the compensation plate is adjusted, and an interference image with clear imaging is obtained on the CCD; a reflector is then adjusted to enable the dip angle of the deflected light beam to change, different optical path differences are introduced into the test light through the compensation plate, and different phase shifting quantities are introduced into an interference graph; and the phase position is restored through a phase-shifting algorithm after the series of phase-shifting interference graphs are collected. The device has the advantages of being low in cost, compact instructure and good in contrast ratio. The operation is simple and convenient, and the device and method can be widely applied to the field of wavefront high-precision detection.

Variable-dip-angle phase-shifting mach-zehnder interferometer measuring device and method

A simultaneous phase-shifting Twyman interferometer with a point source array is proposed. We use a point source in combination with a grating and select the four (±1,±1) diffraction orders to generate a point source array. With this configuration, we can acquire four independent Twyman interferometers. Adjust the offset amounts of each point source to introduce different phase shifts in the interferograms, and realize dynamic measurement. We introduce 0, π/2, π, and 3π/2 in the interferograms. The initial phase will be exactly retrieved by employing the four-bucket algorithm. The experimental results show the feasibility and precision of the interferometer.

Simultaneous phase-shifting Twyman interferometer with a point source array

The invention discloses a point light source ectopic Mach-Zehnder interferometer measurement device and method The device comprises a point light source, a light splitting assembly, a main interferometer and a light splitting imaging assembly The method comprises steps that firstly, spherical waves are emitted by the point light source, and the point light source is copied by the light splitting assembly into four identical point light sources; secondly, through adjusting distances of the four point light sources on a collimation object lens focal plane of the main interferometer and on an optical axis, corresponding phase shift amount is introduced to interference of a reference plane and a test plane; lastly, four intelligible imaging phase shift interferograms are simultaneously acquired on one CCD through the light splitting assembly The device and the method are advantaged in that low cost, good anti-vibration performance, good contrast and easy operation are realized, and the device can be applied to the air flow density change measurement field

Point light source ectopic Mach-Zehnder interferometer measurement device and method

The invention discloses a Twyman type point source array ectopic synchronous phase shift interferometer and measurement method thereof, belonging to the field of optical interference measuring instruments. The interferometer includes a point light source and a beam-splitting component of the point light source, a Twyman type main interferometer and a beam-splitting imaging assembly. The method includes that the spherical wave emitted by the point light source is splitted by the beam-splitting component into four beams and then enters the main interferometer, and the point light source can be copied by the beam-splitting component copies into four, by adjusting the distance from the four point light sources to an optical axis on the collimating object lens focal plane of the main interferometer, different phase shift amount is introduced into the interference of the reference plane and the test plane, and then four clearly cleaned phase shift interferograms are acquired on one CCD at the same time through the beam-splitting imaging assembly. The Twyman type point source array ectopic synchronous phase shift interferometer has the characteristics of low cost, good resistance to shock, good contrast, and easy operation, and can be applied to the field of the real-time high-precision detection of optical components.

Ding Yu

Papers

Simultaneous phase-shifting Twyman interferometer with a point source array

Point light source ectopic Mach-Zehnder interferometer measurement device and method

Twyman type point source array ectopic synchronous phase shift interferometer and measurement method thereof

Point source heterotopic beam expansion synchronous phase shift fizeau interferometer and measurement method thereof

Dynamic Fizeau interferometer using low-coherence light source