Fast scanning method for one-dimensional surface profile measurement by detecting angular deflection of a laser beam

Area of Science:

• Optics and Photonics
• Metrology
• Surface Science

Background:

• Accurate surface profile measurement is crucial for quality control in manufacturing and research.
• Existing methods can be slow, costly, or sensitive to environmental factors like vibration.

Purpose of the Study:

• To introduce a novel, high-speed, and cost-effective method for one-dimensional surface profile measurement.
• To demonstrate the method's accuracy and robustness compared to established techniques.

Main Methods:

• A scanning optical system employing a spherical concave mirror and a rotating scanner mirror was developed.
• Surface slope distribution was obtained via angular deflection of a scanning laser beam.
• The surface profile was reconstructed by integrating the measured slope distribution.

Main Results:

• The developed scanning method achieved high-speed measurements within milliseconds.
• A polygonal mirror's surface profile over a 5-mm width was successfully measured.
• The root-mean-square difference between the proposed method and interferometry was 0.98 nm.

Conclusions:

• The proposed fast scanning method provides accurate and reliable one-dimensional surface profile measurements.
• The system's low cost and insensitivity to mechanical vibration make it suitable for practical applications.
• This technique offers a viable alternative for high-speed surface metrology.