Coherent two-beam interference fringe projection for highspeed three-dimensional shape measurements

Area of Science:

• Optics and Photonics
• Metrology
• High-Speed Imaging

Background:

• Two-beam interference is a foundational optical principle for generating Fizeau fringes.
• Mach-Zehnder interferometers are established tools for optical measurements.
• Current high-speed 3D measurement techniques face limitations in speed and accuracy.

Purpose of the Study:

• To develop and evaluate a novel high-speed 3D shape measurement technique.
• To leverage Fizeau fringes generated via two-beam interference for precise measurements.
• To assess the performance of this method against existing technologies like digital light processing projectors.

Main Methods:

• Utilized a Mach-Zehnder interferometer to generate Fizeau interference fringes.
• Incorporated an acousto-optical deflector for rapid phase shifting of fringes (up to 200,000 Hz).
• Employed high-speed cameras for stereo-photogrammetric data acquisition.

Main Results:

• Demonstrated a stereo-photogrammetric approach capable of high-speed 3D shape measurement.
• Achieved high fringe shifting rates, enabling capture of fast dynamic events.
• Experimental results validated the technique's suitability, accuracy, and speed.

Conclusions:

• The developed technique offers a viable and effective solution for high-speed 3D shape measurements.
• This method shows significant advantages over conventional stripe projection techniques for dynamic scenarios.
• The study substantiates the potential of interferometric fringe manipulation for advanced metrology.