A method for phase reconstruction from measurements obtained using a configured detector with a scanning transmission...

Area of Science:

• X-ray microscopy
• Phase contrast imaging
• Quantitative phase reconstruction

Background:

• Differential phase contrast (DPC) imaging in scanning transmission X-ray microscopy (STXM) provides information about specimen phase shifts.
• Quantitative phase reconstruction from DPC images is challenging due to the derivative nature of the signal.

Purpose of the Study:

• To develop and demonstrate a novel technique for quantitative phase reconstruction from DPC images in STXM.
• To enable accurate determination of specimen phase thickness using DPC data.

Main Methods:

• Utilized geometric optics to model X-ray beam interaction with the specimen.
• Interpreted measured intensities as derivatives of phase thickness.
• Employed Fourier integration techniques to reconstruct the phase from directional derivatives.

Main Results:

• Successfully reconstructed quantitative phase information from simulated DPC measurements.
• Demonstrated the technique on a 0.5-µm-diameter gold sphere at 7-keV photon energy.
• Validated the accuracy of the phase reconstruction method.

Conclusions:

• The developed technique provides a robust method for quantitative phase reconstruction in STXM.
• This approach advances the capability of DPC imaging for materials characterization.
• Accurate phase reconstruction opens new avenues for analyzing nanoscale structures.