Phase-shifting interferometer based on changing the direction of linear polarization orthogonally.
TL;DR: A new type of phase-shifting interferometer is presented, which utilizes a polarizing prism to form quadrature phase- shifted fringe patterns onto a single imaging sensor, and it is possible to reduce phase errors caused by mechanical vibrations and air turbulence.
Abstract: We present a new type of phase-shifting interferometer, which utilizes a polarizing prism to form quadrature phase-shifted fringe patterns onto a single imaging sensor. By changing the direction of linear polarization of the incident light orthogonally, four phase-shifted fringe patterns in quadrature are obtained by taking images twice; thus it is possible to reduce phase errors caused by mechanical vibrations and air turbulence that occur in temporal phase-shifting interferometers. We present the principle of this interferometer with its theoretical analysis, using the Jones matrix, along with experimental results.
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Journal Article•
TL;DR: In this article, a fast Fourier transform method of topography and interferometry is proposed to discriminate between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour generation techniques.
Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.
3,742 citations
TL;DR: This method is computationally fast, applicable to any phase-shifting algorithm and interferometer geometry, has few restrictions on surface shape, and unlike spatial Fourier methods, high density spatial carrier fringes are not required, although at least a fringe of phase departure is recommended.
Abstract: A general method for reducing the influence of vibrations in phase-shifting interferometry corrects the surface phase map through a spectral analysis of a “phase-error pattern,” a plot of the interference intensity versus the measured phase, for each phase-shifted image. The method is computationally fast, applicable to any phase-shifting algorithm and interferometer geometry, has few restrictions on surface shape, and unlike spatial Fourier methods, high density spatial carrier fringes are not required, although at least a fringe of phase departure is recommended. Over a 100× reduction in vibrationally induced surface distortion is achieved for small amplitude vibrations on real data.
82 citations
TL;DR: A new method for phase-shifting interferometry based onWave amplitude modulation based on wave amplitude modulation is proposed and discussed, and both a theoretical model and some numerical simulations are presented.
Abstract: A new method for phase-shifting interferometry based on wave amplitude modulation is proposed and discussed. This proposal is based on the interference of three waves, where two waves attend as two reference waves and the other wave attends as a probe wave. Thereby, three interference terms are obtained, but because a phase difference of π/2 between the two references is kept constant, one of the three terms will be dropped, while the two remaining will be put in quadrature. Under these conditions, the resulting pattern is mathematically modeled by an interferogram of two waves, where an additional phase is given by the amplitude variations of the reference waves. In this Letter, both a theoretical model and some numerical simulations are presented.
30 citations
TL;DR: A new scheme for parallel phase-shifting interferometry is presented that employs a Michelson-like architecture and a simple polarization unit to generate twophase-sh shifting interferograms with phase shift of π/2 at a single camera exposure.
Abstract: In this paper, we present a new scheme for parallel phase-shifting interferometry that employs a Michelson-like architecture and a simple polarization unit to generate two phase-shifting interferograms with phase shift of π/2 at a single camera exposure. The parallel phase-shifting unit is built with simple optical components, and the distance between the parallel interferograms can be adjusted conveniently. Phase reconstruction is performed by using an algorithm developed for two-step phase-shifting interferometry. The practicability of the proposed configuration and the reconstruction method is demonstrated by experiments.
29 citations
Cites methods from "Phase-shifting interferometer based..."
...Based on the polarization phase-shifting principle [19], perpendicularly linearly polarized object and reference waves are used to generate the phase-shifting interferograms....
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...According to the polarization phase-shifting principle [19], the two parallel interferograms have a phase shift of π=2 between each other, as is shown in Fig....
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TL;DR: A method for characterizing the phase response of spatial light modulators (SLMs) by using a Sagnac interferometer is proposed and demonstrated and represents an improvement over conventional diffraction-based or interferometric techniques.
Abstract: A method for characterizing the phase response of spatial light modulators (SLMs) by using a Sagnac interferometer is proposed and demonstrated. The method represents an improvement over conventional diffraction-based or interferometric techniques by providing a simple and accurate phase measurement while taking advantage of the inherent phase stability of a Sagnac interferometer. As a demonstration, the phase response of a commercial liquid crystal on a silicon SLM is characterized and then linearized by using a programmable lookup table. The transverse phase profile over the SLM surface is also measured.
24 citations
References
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Journal Article•
TL;DR: In this article, a fast Fourier transform method of topography and interferometry is proposed to discriminate between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour generation techniques.
Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.
3,742 citations
TL;DR: In this paper, a fast Fourier transform method of topography and interferometry is proposed to discriminate between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour generation techniques.
Abstract: A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.
3,650 citations
02 Aug 2004
TL;DR: In this article, a new type of dynamic measurement system that is comprised of a micropolarizer array and can work with any type polarization interferometer to measure a variety of physical properties is presented.
Abstract: We have demonstrated a new type of dynamic measurement system that is comprised of a micropolarizer array and can work with any type polarization interferometer to measure a variety of physical properties. The unique configuration overcomes many of the limitations of previous single frame, phase-shift interferometer techniques. In particular it has a true common path arrangement, is extremely compact, and is achromatic over a very wide range. We demonstrated high quality measurement with both a Twyman-Green and Fizeau type interferometer. The technique is useful for many applications where vibration or motion is intrinsic to the process.
285 citations
TL;DR: In this article, an instantaneous phase measuring interferometer (PMI) was proposed to measure displacements at one point to a resolution of 0.003 um, with a measurement time aperture of less than 1 As.
Abstract: Conventional phase measuring interferometry normally requires one-half to sixty seconds acquisition time, limiting measurement to stationary phenomena such as optical element wavefronts. We have developed an instantaneous phase measuring interferometer (PMI) that measures displacements at one point to a resolution of 0.003 um. We describe this instrument and an interferometer measuring phase to X/2000 with a measurement time aperture of less than 1 As. Also described is an attached system for analyzing and displaying wavefronts at up to 10 Hz.
221 citations
101 citations