A large-depth-of-field projected fringe profilometry using supercontinuum light illumination

Area of Science:

• Optical Metrology
• Nonlinear Optics

Background:

• Projected fringe profilometry is a key technique for 3D surface measurement.
• Traditional laser-based systems suffer from limited depth-of-field and speckle noise.
• Supercontinuum light offers unique properties for optical applications.

Purpose of the Study:

• To present a large-depth-of-field projected fringe profilometry system.
• To leverage a supercontinuum light source for enhanced profilometry.
• To demonstrate a highly accurate and robust 3D surface measurement technique.

Main Methods:

• Generating a supercontinuum light source by launching femtosecond laser pulses into nonlinear photonic crystal fiber.
• Utilizing the supercontinuum light's high spatial coherence and broad spectrum to create modulated fringe patterns.
• Developing a projected fringe profilometer system incorporating the supercontinuum source.

Main Results:

• Achieved a large depth-of-field for 3D surface measurements.
• Demonstrated ease of calibration for the profilometry system.
• Significantly reduced speckle noise compared to conventional laser systems.
• Obtained high measurement accuracy.

Conclusions:

• A highly accurate, large-depth-of-field projected fringe profilometer is realized using a supercontinuum light source.
• The proposed method overcomes the limitations of traditional laser-based profilometry.
• The system offers advantages in depth-of-field, calibration, and noise reduction.