Computational vector fiducial for deflectometry system alignment.

Area of Science:

• Optical metrology
• Precision engineering
• Computational imaging

Background:

• Deflectometry excels at measuring dynamic optics without physical references.
• Accurate deflectometry relies heavily on precise calibration procedures.

Purpose of the Study:

• To present a new alignment technique for deflectometry systems using a computational fiducial.
• To eliminate the need for additional hardware in the calibration process through algorithmic innovation.

Main Methods:

• Developing a computational fiducial using ray tracing to establish screen-detector relationships.
• Generating an algorithmic fiducial pattern based on ideal system geometry.
• Quantifying misalignment using G and C vector polynomials and reverse optimization.

Main Results:

• The proposed algorithm successfully aligned a 195mm x 80mm freeform optic.
• Achieved peak-to-valley accuracy within 10 µm.
• Demonstrated the method's effectiveness through simulations and experiments.

Conclusions:

• The computational fiducial-based alignment is a simple yet effective technique.
• This method can be a crucial addition to conventional deflectometry system calibration.
• Algorithmic innovation offers a hardware-free solution for precise optical alignment.