X-ray waveguides based on Bragg scattering of multilayers

Advances in fabrication of X-ray waveguides

“…While waveguide (WG) optics is ubiquitous in the visible and infrared spectral range, it is still much less developed in the x-ray regime, despite some encouraging initial work on planar x-ray WGs [1,2,3,4,5,6,7,8]. This is for a good reason.…”

Advanced x-ray multilayer waveguide optics

“…Generally speaking, these advantages of the novel WGA result in enhancement of the waveguide performance [26,29,32,33], being at the same time a coherence filter and a secondary quasi-focusing device.…”

“…It is well known that a multilayer structure based on Bragg theory can increase the guided intensity [32,33]; also the choice of materials plays an important role: Introducing two Mo layers into a Ge/C /Ge structure can increase the transmission significantly [29] by reducing absorption of the evanescent wave in the cladding.…”

“…Tapered waveguides channels with an exit size down to 16.5 nm × 14.6 nm have been reported recently [23]. In [30,31], the single guiding film was generalized to an array of planar wavguides, and in [32,33], the cladding was generalized to a multilayer structure.…”

“…With thin film deposition techniques, notably 8 nm [27,28] for the given material could be reached in a planar thin film waveguide with an optimized cladding material (Mo/C /Mo structure embedded in Ge wafers [29]). Furthermore, the single guiding film [30,31] or the cladding film [32,33] can be generalized to a multilayer structure. Therefore, for purposes of the highest beam confinement or to exploit novel geometries as in this thesis, waveguiding in only one dimension as in an array of thin planar films, is suitable and attractive, owing to a better control of layer sequences.…”