Related Experiment Video
Updated: Jun 19, 2026

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating
Published on: October 11, 2016
Characteristics of crystallographic gratings
Abstract:
We report the observation and characterization of a resonance effect in gratings fabricated on GaAs substrates by use of a crystallographically preferential wet chemical etch that terminates at the (111) family of planes. Also, we demonstrate an in situ etch-monitoring study of the diffraction characteristics of these gratings. The light intensity in the first order of diffraction was monitored in Littrow reflection during etching at 632.8- and 543.5-mm wavelengths. Scanning-electron microscopy was performed on several samples to correlate the etch depth with diffraction efficiency. The variation of diffraction intensity with depth showed a narrow peak at a shallower grating depth and a broader peak at a larger grating depth. These diffraction characteristics are explained on the basis of a competitive interaction between the resonance effect of the incident optical mode and the magnitude of the first Fourier component of the grating profile that primarily couples the incident and diffracted optical modes.
Related Concept Videos
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...
Determination of Crystal Structures
The Seven Crystal Systems: Overview
Imperfections in Crystal Structure: Point, Line and Plane Defects
Crystallographic Point Groups
X-ray Diffraction of Biological Samples
According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...

