Form determination of optical surfaces by measuring the spatial coherence function using shearing interferometry

Area of Science:

• Optical Engineering
• Metrology

Background:

• Accurate form measurement of optical surfaces is crucial for high-performance optical systems.
• Traditional interferometric methods can be complex and sensitive to environmental factors.

Purpose of the Study:

• To introduce a new method for optical surface form measurement.
• To demonstrate the efficacy of a shearing interferometer combined with LED multispot illumination.
• To validate the inverse raytracing evaluation approach.

Main Methods:

• Utilizing the spatial coherence function for form measurement.
• Employing a shearing interferometer with LED multispot illumination.
• Applying an inverse raytracing algorithm for data evaluation.
• Investigating the convergence and stability of the optimization process.

Main Results:

• Successful demonstration of the measurement principle.
• Presentation of initial measurement results using the inverse evaluation procedure.
• Validation of the integrated measurement and evaluation system.

Conclusions:

• The proposed method provides a viable approach for optical surface form measurement.
• The inverse raytracing evaluation is effective in connecting measurement data to surface form.
• The system demonstrates stability and convergence for practical applications.