Mixed stitching interferometry with correction from one-dimensional profile measurements for high-precision X-ray...

Area of Science:

• Optics and Metrology
• Optical Engineering
• Surface Metrology

Background:

• Stitching interferometry is crucial for measuring large optical surfaces.
• Classic global stitching algorithms can accumulate significant errors in stitching angles.
• Accurate one-dimensional (1D) profile measurements are essential for error correction.

Purpose of the Study:

• To develop and validate a mixed stitching interferometry method incorporating 1D profile correction.
• To reduce stitching angle errors inherent in traditional stitching interferometry.
• To enhance the overall measurement accuracy of optical components.

Main Methods:

• A mixed stitching interferometry approach combining subaperture data.
• Correction of stitching angle errors using 1D profile measurements from contact profilometry.
• Simulation and analysis of measurement accuracy and repeatability.
• Averaging multiple 1D profile measurements at different positions to decrease repeatability error.

Main Results:

• The proposed method effectively corrects stitching angle errors, reducing original profile errors by one-third compared to global stitching.
• Repeatability error was significantly decreased through averaging multiple 1D profile measurements.
• The mixed stitching method demonstrated superior performance in suppressing stitching angle error accumulation.

Conclusions:

• The mixed stitching interferometry method with 1D profile correction offers a robust solution for accurate measurement of optical surfaces.
• High-precision 1D profile measurements, such as those from a nanometer optical component measuring machine (NOM), can further improve accuracy.
• This technique provides a viable alternative to classic global stitching algorithms for high-accuracy optical metrology.