Waveguides are widely used for filtering, confining, guiding, coupling or splitting beams of visible light. However, creating waveguides that could do the same for X-rays has posed tremendous challenges in fabrication, so they are still only in an early stage of development.
In the latest issue of Acta Crystallographica Section A: Foundations and Advances , Sarah Hoffmann-Urlaub and Tim Salditt report the fabrication and testing of a millimetre-sized chip capable of splitting a beam of X-rays [Acta Cryst. (2016), A72, doi:10.1107/S205327331601144X].
Fork-shaped channels that are only a few tens of nanometres wide and deep are transferred into a silicon wafer using electron-beam lithography and reactive ion etching then enclosed by bonding a second silicon wafer on top.
The results of simulations of how the 'parent' beam is split into two 'daughter' beams on passing through the chip were backed up by experimental measurements at the European Synchrotron Radiation Facility, showing that the incident beam is efficiently transported through the chip, neatly split and guided to exits that have precisely controlled (and tunable) spacings.
After the daughter beams leave the chip, they interfere, leading to a pattern of vertical stripes just like the pattern obtained from a classical Young's double-slit interference experiment. Interestingly, on close inspection there are fork-like structures within the stripes that originate from discontinuities in the phase of the recombined beam, forming striking features known as phase vortices.
Furthermore, from those interference patterns the intensity distribution in the exit plane of the channels is reconstructed, which is found to be in very good agreement to the actual channel design.
This study complements earlier work on two-dimensionally confined channels in silicon in straight and tapered geometries, and paves the way to realizing `X-ray optics on a chip'. Illumination of samples by the two beams could provide some interesting advantages for coherent imaging and opens up the possibility of a new form of nano-interferometer.
The authors envisage future development of their beamsplitter to create several daughter beams from the same parent beam, which would allow a single object to be imaged simultaneously by several beams, each from a different direction.
Dr. Jonathan Agbenyega | EurekAlert!
Further Improvement of Qubit Lifetime for Quantum Computers
09.12.2016 | Forschungszentrum Jülich
Electron highway inside crystal
09.12.2016 | Julius-Maximilians-Universität Würzburg
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine