Optics metrology and at-wavelength wavefront characterization by a microfocus X-ray grating interferometer

Area of Science:

• Optics
• Metrology
• Materials Science

Background:

• Accurate characterization of X-ray optical elements is crucial for advanced imaging and experimental techniques.
• Existing methods may lack the precision or in situ capabilities required for modern X-ray optics.

Purpose of the Study:

• To introduce and validate a microfocus X-ray grating interferometer (MFXGI) for precise X-ray wavefront and optical element metrology.
• To demonstrate the MFXGI's capability for in situ analysis of optical element performance.

Main Methods:

• The MFXGI utilizes a phase grating (G1) and an absorption grating (G2) with a position-sensitive detector.
• It employs a microfocus X-ray source to simultaneously capture direct and reflected beams.
• Wavefront distortions from a deformable mirror were analyzed under operational conditions.

Main Results:

• The MFXGI successfully measured X-ray wavefront profiles and slope errors.
• Simultaneous capture of direct and reflected beams enabled comprehensive analysis.
• Analysis of direct beams allowed for calculation of parameter errors, spherical shapes, and retrieval of aspherical profiles.

Conclusions:

• The MFXGI is a valuable instrument for in situ characterization of X-ray optical elements.
• This technology is expected to advance X-ray adaptive optics and mirror manufacturing.
• The MFXGI provides a robust method for error compensation and shape retrieval of X-ray optics.