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Endoscopic pulsed digital holography for 3D measurements
Optics Express
|June 9, 2009
Summary
Pulsed digital holography with a rigid endoscope measures three displacement components in hidden areas of a vibrating metallic cylinder. This method uses three illumination positions and incoherent recording for simultaneous 3D displacement analysis.
Area of Science:
- Optical Engineering
- Metrology
- Mechanical Vibration Analysis
Background:
- Measuring displacement in hidden or inaccessible areas is challenging.
- Pulsed digital holography offers high-resolution, non-contact measurement capabilities.
Purpose of the Study:
- To develop a method for measuring three orthogonal displacement components in hidden areas.
- To enable simultaneous 3D displacement information acquisition using pulsed digital holography.
Main Methods:
- Utilized a rigid endoscope and three distinct object illumination source positions.
- Employed pulsed digital holography with incoherent mismatching of reference-object beam pairs.
- Recorded three pulsed digital holograms incoherently within a single CCD sensor frame.
- Applied the Fourier method and hologram subtraction to determine phase differences.
Main Results:
- Successfully measured the three orthogonal displacement components of a harmonically vibrating metallic cylinder.
- Achieved simultaneous 3D displacement information from hidden areas.
Conclusions:
- The proposed pulsed digital holography technique is effective for 3D displacement measurement in hidden regions.
- The method allows for non-contact, high-resolution analysis of vibrating structures.
