3D shape measurement of macroscopic objects in digital off-axis holography using structured illumination

Area of Science:

• Optics and Photonics
• 3D Metrology
• Computational Imaging

Background:

• Holographic setups are widely used for optical measurements.
• Accurate 3D shape measurement of macroscopic objects remains a challenge.
• Existing methods may have limitations in object complexity or data density.

Purpose of the Study:

• To introduce a novel holographic approach for dense 3D shape measurement.
• To demonstrate the method's capability for arbitrary diffuse-reflecting objects.
• To validate the technique through quantitative results and complex object analysis.

Main Methods:

• Utilizing a standard holographic setup augmented with a CCD camera.
• Employing a liquid-crystal-on-silicon spatial light modulator to modulate the object wave.
• Implementing a calibration process for accurate 3D point cloud generation.

Main Results:

• The method successfully generates dense 3D point clouds of objects and scenes.
• Quantitative results demonstrate the accuracy of the shape measurement.
• A complex object's shape was measured, showcasing the method's universal applicability.

Conclusions:

• The proposed holographic technique offers a novel and effective solution for 3D shape measurement.
• The use of a spatial light modulator enhances the density and accuracy of 3D reconstructions.
• This method shows significant potential for diverse applications in 3D metrology.