Nonnull interferometer simulation for aspheric testing based on ray tracing.

Area of Science:

• Optical Engineering
• Metrology
• Interferometry

Background:

• Nonnull interferometric methods are valuable for aspheric testing but require accurate system modeling for error correction.
• Existing methods face challenges in precisely simulating retrace errors and reconstructing aspheric fabrication errors.

Purpose of the Study:

• To propose a novel ray-tracing-based method for simulating nonnull interferometers.
• To accurately model and correct retrace errors and reconstruct aspheric fabrication errors, including non-rotationally symmetric ones.

Main Methods:

• Developed a ray-tracing approach to calculate optical path difference by tracing rays through reference and test paths.
• Mathematically represented non-rotational symmetric fabrication errors using Zernike polynomials (Zernike deformation).
• Derived ray-tracing formulas for deformed surfaces, accommodating misalignment (tilts and decenters) for enhanced system modeling.

Main Results:

• The proposed method accurately simulates nonnull interferometers, calculating optical path differences.
• Successfully modeled and simulated systems with varying magnitudes of Zernike deformations.
• Simulation results validated against Zemax, demonstrating the method's correctness and effectiveness.

Conclusions:

• The ray-tracing-based simulation method offers a robust solution for modeling nonnull interferometers.
• This technique effectively handles complex aspheric errors and misalignments, crucial for precise optical testing.
• The method facilitates accurate system modeling and error reconstruction in aspheric metrology.