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Updated: May 19, 2026
10:16
Digital Inline Holographic Microscopy (DIHM) of Weakly-scattering Subjects
Published on: February 8, 2014
Contouring of diffused objects using lensless Fourier transform digital moiré holography
Md Mosarraf Hossain1, Gyanendra Sheoran, Varun Kumar
1Space Physics Laboratory, Vikram Sarabhai Space Center, Thiruvananthapuram, Kerala, India.
Applied Optics
|August 4, 2012
Summary
This study introduces a novel digital holographic moiré interferometry method for contouring diffused objects. The technique effectively measures object details across a large dimensional range, offering precise contour intervals.
Area of Science:
- Optics and Photonics
- Metrology
- Materials Science
Background:
- Contouring of diffused objects presents challenges in metrology.
- Digital holographic techniques offer advanced solutions for surface profiling.
Purpose of the Study:
- To propose and validate a new method for contouring diffused objects using digital holographic moiré interferometry.
- To demonstrate the capability of measuring objects with large dimensional ranges and varying detail sizes.
Main Methods:
- Utilizing a lensless Fourier transform configuration with fringe projection moiré and digital double-exposure holography.
- Recording three digital holograms with slight variations in illumination angle and detector position.
- Numerical processing of holograms to generate modified and reference grids, leading to moiré contour fringes.
Main Results:
- Successfully generated moiré contour fringes for an aluminum alloy cube.
- Achieved contour intervals ranging from 2.73 mm to 0.38 mm, with seven distinct contours.
- Demonstrated the method's applicability to objects of large dimensions and varied detail sizes.
Conclusions:
- The proposed digital holographic moiré interferometry method is effective for contouring diffused objects.
- The technique provides accurate measurements with deviations within 12%-18% from theoretical values.
- Potential for measuring diverse object sizes and details with high precision.
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