학술논문

X-ray waveguide arrays: tailored near fields by multi-beam interference.
Document Type
Article
Source
XRS: X-ray Spectrometry. Mar/Apr2017, Vol. 46 Issue 2, p107-115. 9p.
Subject
*WAVEGUIDES
*X-rays
*NEAR-fields
*OPTICAL interference
*MAGNETRON sputtering
*AMORPHOUS carbon
*MOLYBDENUM
Language
ISSN
0049-8246
Abstract
A novel 1-D X-ray waveguide, the Mo/C waveguide array (WGA), is introduced to tailor the optical near field distribution by precisely designed and controlled multi-beam interference at 19.9 keV hard X-ray energy. Seven precisely controlled guiding layers with optimized layer thickness variation were fabricated by high-precision direct-current magnetron sputtering of amorphous carbon (C) and molybdenum (Mo). The thickness variations are designed in such a way to introduce the desired phase shifts between the guided output beams, to act as a quasi-focusing device. The WGA and the layer thicknesses are characterized by X-ray reflectivity, transmission electron microscopy, and measurement of the synchrotron radiation far-field intensity pattern. Based on the measurements and simulations, a reliable Mo/C multilayer layers combination can be verified. With the layers thicknesses, simulations inside the WGA and in the optical near field behind it show that multi-beam interference with the designed phase shifts lead to a relative beam intensity of 0.59 in a quasi-focal plane 0.08 mm behind the exit, with a spot size of 23.8 nm. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]