A non-iterative method for phase-shift estimation and wave-front reconstruction in phase-shifting digital holography

2006 ◽  
Vol 268 (2) ◽  
pp. 231-234 ◽  
Author(s):  
Shuqun Zhang
Keyword(s):  
Phase Shift ◽  
Iterative Method ◽  
Wave Front ◽  
Digital Holography ◽  
Phase Shifting

Determination of Phase Shift by Digital Holography

2019 ◽  
Vol 888 ◽  
pp. 43-46
Author(s):  
Yoshitaka Takahashi ◽  
Masatoshi Saito ◽  
Toru Nakajima ◽  
Masakazu Shingu
Keyword(s):  
Phase Shift ◽  
Noise Reduction ◽  
Digital Holography ◽  
High Accuracy ◽  
Measured Data ◽  
Phase Shifting ◽  
Surface Shape ◽  
Shape Measurement ◽  
Phase Shifting Interferometry

In phase shifting interferometry phase shift is applied by various ways, but applying it with high accuracy, especially by LD current modulation, is not easy. In order to determine the accurate phase shift a new method has been proposed that the value of LD current corresponding to π/2 phase shift can be determined by phase shifting digital holography. The measured data of standard in surface shape measurement were used for calibration, and the obtained value was confirmed to cause noise reduction and improvement of holographic reconstructed images in digital holography.

A method of hard X-ray phase-shifting digital holography

2016 ◽  
Vol 23 (4) ◽  
pp. 1024-1029
Author(s):  
So Yeong Park ◽  
Chung Ki Hong ◽  
Jun Lim
Keyword(s):  
Phase Shift ◽  
Digital Holography ◽  
Relative Phase ◽  
Test Pattern ◽  
Fresnel Lens ◽  
Phase Shifting ◽  
New Method ◽  
Phase Plate ◽  
X Ray ◽  
Line Type

A new method of phase-shifting digital holography is demonstrated in the hard X-ray region. An in-line-type phase-shifting holography setup was installed in a 6.80 keV hard X-ray synchrotron beamline. By placing a phase plate consisting of a hole and a band at the focusing point of a Fresnel lens, the relative phase of the reference and objective beams could be successfully shifted for use with a three-step phase-shift algorithm. The system was verified by measuring the shape of a gold test pattern and a silica sphere.

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

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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