Micro-nano Scale Longitudinal Displacement Measurement of Microspheres Based on Digital Holography

Phase-shifting digital holography can be used for displacement measurement instead of strain gauge. Our research group is developing the measurement equipment for phase-shifting digital holography. Generally, in the measurement equipment, piezo stages are used as phaseshifting devices. But the piezo stage is expensive. Cheaper and smaller phase-shifting device is required in order to put the measurement equipment into practical use. In this paper, we, therefore, propose a phase-shifting device using the deflection of a cantilever and we verify whether this phase-shifting device can be usedfor digital holography.

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Three-dimensional displacement measurement for diffuse object using phase-shifting digital holography with polarization imaging camera

Applied Optics ◽

10.1364/ao.50.00h189 ◽

2011 ◽

Vol 50 (34) ◽

pp. H189 ◽

Cited By ~ 13

Author(s):

Tomohiro Kiire ◽

Suezou Nakadate ◽

Masato Shibuya ◽

Toyohiko Yatagai

Keyword(s):

Digital Holography ◽

Three Dimensional ◽

Displacement Measurement ◽

Phase Shifting ◽

Polarization Imaging ◽

Imaging Camera

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Phase-Shifting Method with Unknown Intervals in Phase-Shifting Digital Holography

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.3-4.211 ◽

2006 ◽

Vol 3-4 ◽

pp. 211-216

Author(s):

T. Kita ◽

Yoshiharu Morimoto ◽

Motoharu Fujigaki ◽

Toru Matui

Keyword(s):

Phase Shift ◽

Intensity Distribution ◽

Digital Holography ◽

Phase Distribution ◽

Reference Beam ◽

Spherical Wave ◽

High Accuracy ◽

Displacement Measurement ◽

Phase Shifting ◽

Phase Shifting Method

Displacement measurement can be performed with high accuracy using phase-shifting method. In phase-shifting method, it is often used four steps of phase-shifting for one cycle. In conventional method, to measure the displacement of an object by an interferometer, the phase of a reference beam should be shifted by every π/2 in the four-step phase-shifting. In this paper, a phase-shifting method with unknown intervals is proposed. This method does not need to shift a phase by every π/2. It can detect an intensity distribution and a phase distribution from five fringe images with equal intervals even if the phase-shift amount is unknown. Using this method, we propose a displacement measurement of phase-shifting digital holographic interferometry using spherical wave as reference wave.

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