Related Experiment Video
Updated: Jan 25, 2026

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating
Published on: October 11, 2016
Time-resolved X-ray reflection phases of the nearly forbidden Si(222) reflection under laser excitation
Yi Wei Tsai1, Ying Yi Chang1, Jey Jau Lee1
1National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan.
Abstract:
The covalent electron density, which makes Si(222) measurable, is subject to laser excitation. The three-wave Si(222)/(13 {\overline 1}) diffraction at 7.82 keV is used for phase measurements. It is found that laser excitation causes a relative phase change of around 4° in Si(222) in the first 100 ps of excitation and this is gradually recovered over several nanoseconds. This phase change is due to laser excitation of covalent electrons around the silicon atoms in the unit cell and makes the electron density deviate further from the centrosymmetric distribution.
More Related Videos
Related Concept Videos
Reflection of Waves
The Sense of Self: Reflected Self-Appraisal and Social Comparison
Total Internal Reflection Fluorescence Microscopy
Attenuated Total Reflectance (ATR) Infrared Spectroscopy: Overview
The ATR process begins by directing a beam...
X-ray Crystallography
Diffraction
Diffraction is the change in the direction of travel experienced by an electromagnetic wave when it encounters a physical barrier whose dimensions are comparable to those of the wavelength of the light. X-rays are electromagnetic radiation with wavelengths about as long as the distance between neighboring...
Phase Transitions

