Improved zonal integration method for high accurate surface reconstruction in quantitative deflectometry

Area of Science:

• Optics and Photonics
• Metrology
• Surface Science

Background:

• Quantitative deflectometry uses CCD detectors to sample optical components, leading to unequal sampling intervals in off-axis configurations.
• Traditional Southwell zonal integration methods introduce reconstruction errors with unequal sampling intervals.

Purpose of the Study:

• To propose and validate an improved zonal integration method for quantitative deflectometry.
• To enhance the accuracy of optical surface reconstruction, particularly for non-rectangular apertures and local surface features.

Main Methods:

• Development of an improved zonal integration algorithm.
• Simulations of surface reconstruction for spherical, hyperbolic, and flat surfaces.
• Experimental validation using optical components with unequal sampling points.

Main Results:

• The improved zonal method significantly enhances reconstruction accuracy compared to the traditional zonal method, especially for circular apertures.
• Experimental results confirm superior accuracy of the proposed method over traditional zonal and modal methods.
• The improved method effectively reconstructs local surface details, such as minor scratches.

Conclusions:

• The proposed improved zonal method offers superior accuracy and local detail reconstruction capabilities in quantitative deflectometry.
• This method is particularly beneficial for analyzing optical components with complex geometries and off-axis configurations.
• The findings advance metrology techniques for high-precision optical surface characterization.