High-Sensitivity X-ray Phase Imaging System Based on a Hartmann Wavefront Sensor

Martin Piponnier,Philippe Zeitoun,Laura Oudjedi,Fabrice Harms,Xavier Levecq,Ginevra Begani Provinciali,Alessia Cedola,Ombeline De La Rochefoucauld

doi:10.3390/condmat7010003

Abstract

The Hartman wavefront sensor can be used for X-ray phase imaging with high angular resolution. The Hartmann sensor is able to retrieve both the phase and absorption from a single acquisition. The system calculates the shift in a series of apertures imaged with a detector with respect to their reference positions. In this article, the impact of the reference image on the final image quality is investigated using a laboratory setup. Deflection and absorption images of the same sample are compared using reference images acquired in air and in water. It can be easily coupled with tomographic setups to obtain 3D images of both phase and absorption. Tomographic images of a test sample are shown, where deflection images revealed details that were invisible in absorption. The findings reported in this paper can be used for the improvement of image reconstruction and for expanding the applications of X-ray phase imaging towards materials characterization and medical imaging.

Highlights

IntroductionA wavefront sensor is a device capable of measuring the phase of the incoming light [1]
A wavefront sensor is a device capable of measuring the phase of the incoming light [1].Several techniques have been proposed to measure the incident wavefront in the X-ray regime
We focus on the implementation of a Hartmann wavefront sensor for X-ray phase imaging

Summary

Introduction

A wavefront sensor is a device capable of measuring the phase of the incoming light [1]. Several techniques have been proposed to measure the incident wavefront in the X-ray regime. For soft X-ray lasers Hartmann sensors have been tested with an array of holes [2,3,4,5], zone plate [6]. Curvature sensors [8], which measure the Laplacian of the phase, and two-dimensional interferometers [9,10] based on two orthogonal phase gratings can be implemented to measure the wavefront of an X-ray beam [11,12]. We focus on the implementation of a Hartmann wavefront sensor for X-ray phase imaging

Methods

Results

Discussion

Conclusion