Pupil matching of Zernike aberrations

Area of Science:

• Optical Engineering
• Metrology
• Image Science

Background:

• Wavefront measurement is crucial for assessing optical system performance.
• Comparing sensor data to simulations or interferometry is common but can be affected by alignment errors.
• Residual differences after subtraction often stem from coordinate system mismatches.

Purpose of the Study:

• To present a novel method for numerically canceling small alignment errors in wavefront measurements.
• To utilize Zernike expansion for correcting coordinate system mismatches.
• To quantify the accuracy of a Shack-Hartmann wavefront sensor using this method.

Main Methods:

• Wavefronts are expanded using Zernike polynomials.
• A numerical algorithm is developed to cancel coordinate system misalignments.
• The method is applied to evaluate a custom Shack-Hartmann wavefront sensor.

Main Results:

• The Zernike expansion method effectively cancels small alignment errors between wavefront measurements.
• This technique improves the accuracy of comparing sensor data to known aberration functions.
• The accuracy of a Shack-Hartmann sensor was successfully quantified.

Conclusions:

• Zernike expansion offers a robust solution for mitigating alignment errors in wavefront analysis.
• The developed method enhances the reliability of optical system performance evaluation.
• Accurate wavefront measurement is critical for advanced optical system characterization.