Modern approaches in phase measuring metrology (Invited Paper)

Millerd, James E.; Brock, Neal; Hayes, John; Kimbrough, Brad; Novak, Matt; North-Morris, Michael; Wyant, James C.

doi:10.1117/12.621581

Cited by 38 publications

(15 citation statements)

References 6 publications

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“…In the last few years new PSI techniques have been developed that can be applied in the presence of vibrations. The basic idea of all these new techniques is to record the sequence of interferograms in a very short time interval [2] or even simultaneously [4], [5], [8] resulting in the effect of shifting the sensitivity of the system to higher frequencies.…”

Section: Vibration Tolerant Methodsmentioning

confidence: 99%

Phase-shift Fizeau interferometer in presence of vibration

2008

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In the context of this article we demonstrate a novel Fizeau interferometric system that copes with the presence of vibrations. Besides the conventional high spatial, but low temporal resolution detector system (the CCD camera) used in phase shifting interferometry, an additional high temporal, but low spatial resolution detector system was integrated, in order to measure the random phase shifts that are induced under the influence of the vibrations. The additional sensor consists of three photodiodes. The acquired analog signals enable the measurement of the occurring phase shifts at three non-collinear locations on the test surface. The resulting phase shifts at the three individual locations enable the determination of the random phase shifts over the entire image aperture. To avoid the smear phenomenon at very short exposure time, a beam shutter was integrated. Another alternative is to integrate a pulsed laser diode, for this purpose the concept of a wavelength meter is proposed. While the random oscillations of the test object are continuously measured, the CCD camera acquires several interferograms. In consequence, a phase shifting algorithm for random phase shifts was applied. In order to proof the validity of the new interferometer, a test surface of known topography was measured. The results of the measurements in presence of vibrations show very good concordance with the surface data given by the supplier. The analysis of the root mean square (RMS) over ten different measurement show a measurement repeatability of about 0.004 waves (approximately 2.5 nm for 632.8 nm laser wavelength).

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Section: Vibration Tolerant Methodsmentioning

confidence: 99%

Phase-shift Fizeau interferometer in presence of vibration

2008

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“…The errors produced by air turbulences were reduced by averaging multiple measurements. An enhanced version of this system is presented in [4] . The basic concept is a combination of polarising and non-polarising beamsplitters and retardation plates to introduce phase shifts.…”

Section: Four Interferograms On Four Image Sensorsmentioning

confidence: 99%

Random-phase-shift Fizeau interferometer

Doloca

Tutsch

2008

SPIE Proceedings

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In the context of this article we demonstrate a novel Fizeau interferometric system that copes with the presence of vibrations. Besides the conventional high spatial, but low temporal resolution detector system (the CCD camera) used in phase shifting interferometry, an additional high temporal, but low spatial resolution detector system was integrated, in order to measure the random phase shifts that are induced under the influence of the vibrations. The additional sensor consists of three photodiodes. The acquired analog signals enable the measurement of the occurring phase shifts at three non-collinear locations on the test surface. Under the assumption of the rigid body shifts and tilts of the test object, the resulting phase shifts at the three individual locations enable the determination of the random phase shifts over the entire image aperture. While the random oscillations of the test object are continuously measured, the CCD camera acquires several interferograms. In consequence, a phase shifting algorithm for random phase shifts was applied. In order to prove the validity of the new interferometer, a test surface of known topography was measured. The results of the measurements in presence of vibrations show very good concordance with the surface data given by the supplier. The analysis of the root mean square (RMS) over ten different measurements shows a measurement repeatability of about 0.004 waves (approximately 2.5 nm for 632.8 nm laser wavelength).

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“…Phase shifting interferometry [8][9][10][11][12] has gained considerable importance recently due to it's distinct advantages over static interferogram analysis for optical testing. The CBS interferometer described above can as well be conveniently adapted to be used as a phase shifting interferometer by incorporating a quarter-wave plate and an output polarizer.…”

Section: Polarization Phase Shifting Using the Cbs Interferometermentioning

confidence: 99%

Cube beam-splitter interferometer for phase shifting interferometry

Ghosh

Bhattacharya

2009

J Opt

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A cube beam splitter (CBS), which is more often used in two beam interferometers to generate orthogonally directed light beams, can interestingly be used to construct a two beam interferometer by aligning its beam splitting surface parallel to the direction of propagation of light. It is shown that in such a configuration, an optical sample placed so as to intercept one half of the expanded incident beam may be tested for phase or surface distortions. The proposed set-up can be used as well to construct a phase shifting interferometer by properly incorporating a quarterwave plate and a polarizer for phase shifting, which can then be used to analyze phase or surface irregularities in optical samples. The monolithic design of the proposed interferometer makes it relatively immune to ambient vibrations.

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Modern approaches in phase measuring metrology (Invited Paper)

Cited by 38 publications

References 6 publications

Phase-shift Fizeau interferometer in presence of vibration

Phase-shift Fizeau interferometer in presence of vibration

Random-phase-shift Fizeau interferometer

Cube beam-splitter interferometer for phase shifting interferometry

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