Digital holographic interferometry and speckle interferometry applied on objects with heterogeneous reflecting...

Area of Science:

• Optics and Photonics
• Metrology
• Solid Mechanics

Background:

• Digital holographic and speckle interferometry are crucial for solid object displacement measurement.
• Object surface reflectivity (scattering vs. specular) significantly impacts system design and data acquisition.
• Practical scenarios often involve objects with mixed surface reflectivity within the field of view.

Purpose of the Study:

• To develop and present strategies for simultaneous measurement of solid object displacement in digital holographic and speckle interferometry systems.
• To address the challenges posed by objects exhibiting both scattering and specular reflectivity zones.
• To enable accurate displacement analysis in complex surface scenarios.

Main Methods:

• Illuminating scattered surface zones with a point source.
• Illuminating specular surface zones with a diffuser.
• Developing separate interpretation methods for interferograms generated from different reflectivity types.

Main Results:

• Demonstrated strategies for handling mixed reflectivity in interferometric measurements.
• Generated specific interferograms with distinct characteristics for scattering and specular areas.
• Showcased separate interpretation of interferometric data based on reflectivity type.

Conclusions:

• Effective strategies exist for digital holographic and speckle interferometry on objects with mixed surface reflectivity.
• Tailored illumination and separate data interpretation are key to accurate displacement measurement.
• The sensitivity vector definition must account for differing reflectivity characteristics.