From speckle pattern photography to digital holographic interferometry [Invited].

Area of Science:

• Optics and Photonics
• Mechanical Engineering
• Materials Science

Background:

• Speckles arise from random phase variations in electromagnetic fields due to surface roughness or turbulence.
• While often considered noise in coherent imaging, speckle phenomena possess significant analytical potential.
• Understanding speckle is crucial for advanced optical measurement techniques.

Purpose of the Study:

• To trace the historical development of speckle-based measurement techniques.
• To highlight the transition from basic speckle photography to sophisticated interferometric methods.
• To underscore the utility of speckle patterns in quantitative analysis.

Main Methods:

• Review of speckle photography principles and applications.
• Exploration of speckle interferometry advancements.
• Discussion of digital holographic interferometry methodologies.

Main Results:

• Demonstration of speckle patterns as a valuable tool for measuring physical parameters.
• Illustration of the progression towards higher precision and broader applicability of speckle techniques.
• Establishment of a lineage from early photographic methods to modern digital interferometry.

Conclusions:

• Speckle interferometry and digital holographic interferometry represent significant advancements over traditional speckle photography.
• These techniques offer robust, non-contact methods for analyzing mechanical properties.
• The evolution of speckle analysis continues to drive innovation in metrology and engineering.