A 2 D high accuracy slope measuring system based on a Stitching Shack Hartmann Optical Head

Area of Science:

• Optical metrology
• X-ray optics
• Precision engineering

Background:

• High-quality optical components are crucial for advanced scientific instruments like synchrotrons and Free Electron Lasers (FEL).
• Existing metrology systems face challenges in achieving the required accuracy for extremely smooth surfaces.
• The demand for precise characterization of X-ray mirrors is increasing with the development of next-generation light sources and observatories.

Purpose of the Study:

• To develop and present a novel 2D Slope measuring System for high-accuracy optical metrology.
• To enable automated metrology for demanding optical components used in X-ray applications.
• To achieve a slope error accuracy better than 50 nanoradian root-mean-square (nrad rms).

Main Methods:

• Utilizing a Stitching Shack Hartmann Optical Head (SSH-OH) for precise surface measurement.
• Implementing a 2D measurement strategy to capture slope errors across the optical surface.
• Developing an automated system for efficient and repeatable metrology.

Main Results:

• Demonstrated a 2D Slope measuring System with the SSH-OH.
• Achieved high accuracy in slope error measurement, surpassing the 50 nrad rms threshold.
• Validated the system's capability for characterizing components for synchrotrons, FELs, EUV lithography, and X-ray astronomy.

Conclusions:

• The presented SSH-OH based 2D Slope measuring System offers a viable solution for high-accuracy optical metrology.
• The system meets the stringent requirements for advanced X-ray optics and related fields.
• Automated metrology with sub-50 nrad rms accuracy is achievable for critical optical components.