Digital holography on moving objects: interference contrast as a function of velocity and aperture width

Area of Science:

• Optics and Photonics
• Metrology
• Digital Holography

Background:

• Digital holographic measurements are crucial for analyzing dynamic systems.
• Understanding interference contrast is key to accurate measurements of moving objects.

Purpose of the Study:

• To investigate digital holographic measurements on planar moving objects.
• To analyze the influence of object velocity and aperture width on interference contrast.
• To determine optimal illumination angles for enhanced measurement accuracy.

Main Methods:

• Digital holography with spatial phase shifting.
• Analysis of interference contrast dependence on velocity and aperture width.
• Experimental validation for motion parallel and perpendicular to the optical axis.

Main Results:

• Experimental results align well with theoretical predictions.
• Measurements achieved velocities up to 100 mm/s with low laser power (<1 mW).
• Identified optimal angles to minimize contrast reduction with increasing velocity.

Conclusions:

• Spatial phase shifting enables accurate digital holographic measurements of moving objects.
• The study provides practical insights for optimizing holographic measurement systems.
• Effective determination of optimal illumination angles enhances measurement robustness.