High-speed digital holographic interferometry for vibration measurement.

Area of Science:

• Optical Engineering
• Metrology
• Vibration Analysis

Background:

• Accurate measurement of dynamic deformation is crucial in various engineering fields.
• Traditional vibration measurement techniques can be limited in resolution and scope.
• Digital holographic interferometry offers a non-contact method for full-field deformation analysis.

Purpose of the Study:

• To develop and present a system for vibration measurement using digital holographic interferometry.
• To demonstrate a method for reconstructing object vibration from recorded holographic data.
• To enable precise phase calculation and deformation retrieval for dynamic analysis.

Main Methods:

• Utilizing a 10 W continuous laser and a high-speed CCD camera to record hundreds of holograms.
• Implementing two camera triggering methods to capture holograms at specific vibration phases.
• Applying a two-dimensional digital Fourier-transform method for wavefront phase calculation.
• Reconstructing object deformation from the calculated phase information.

Main Results:

• Successfully recorded dynamic deformations of an object under vibration.
• Demonstrated the capability to calculate wavefront phase and object deformation from holograms.
• Showcased the reconstruction of object vibration by combining deformations at different time instances.
• Established that acquisition speed and exposure time are dependent on vibration frequency.

Conclusions:

• The presented digital holographic interferometry system is effective for vibration measurement.
• The developed methods allow for accurate phase calculation and deformation retrieval.
• The system enables the full reconstruction of object vibration, offering valuable insights into dynamic behavior.