X-ray Optics and ApplicationsThe X-Ray Optics and Applications group of LMN works on various fields of research involving the control of x-rays with ultimate precision. We develop instrumentation for large scale facilities such as synchrotrons and x-ray free electron lasers (X-FELs), by applying nanolithography techniques. This includes x-ray diffractive optics such as Fresnel zone plate lenses for imaging and probing of matter on a micro- and nanometer scale. Our optics are used at many synchrotron beam lines worldwide and hold the resolution record in x-ray microscopy. For applications that do not require ultimate resolution, we pursue novel approaches to obtain very high diffraction efficiencies.
Interferometric imaging techniques using hard x-rays also rely on specialized micro-fabricated gratings. The possibility to use this technique not only with synchrotron radiation but also with incoherent x-rays from tube sources makes the technique interesting for commercial applications. The extreme sensitivity of grating interferometry also provides a powerful tool for x-ray optics metrology and wavefront sensing.
The development of a new generation of x-ray sources based on the x-ray free-electron laser (X-FEL) principle have triggered the development of specialized diffractive optics. In order to withstand the extreme power levels of X-FELs, we make Fresnel zone plates based on diamond substrates. Similar devices are made for applications such as spectral monitoring or beam splitting. The latter is used to build multiple split-and-delay lines for ultra-fast pump-probe experiments with unprecedented timing precision.
For the fabrication of these devices, the X-Ray Optics and Applications Group runs LMN’s high performance electron-beam lithography tool Vistec EBPG 5000PlusES, that is also used by many other internal and external research groups.
Single-shot Monitoring of Ultrafast Processes via X-ray Streaking at a Free Electron LaserThe advent of x-ray free electron lasers has extended the unique capabilities of resonant x-ray spectroscopy techniques to ultrafast time scales. Here, in collaboration between researchers from PSI, Sorbonne Universités, HASYLAB/DESY, Synchrotron SOLEIL, CNRS, and Uppsala University, we report on a novel experimental method that allows retrieving with a single x-ray pulse the time evolution of an ultrafast process, not only at a few discrete time delays, but continuously over an extended time window.
ReferencesFor references see: List of Publications
Research TopicsDiffractive X-ray Lenses
• Electroplated Zone Plates and Beam Shapers
• Ultra-high Resolution Zone Plates
• Double-Sided Zone Plates
• Blazed X-ray Optics
• Zernike X-ray Phase Contrast Microscopy
Grating-based X-ray Interferometry
• Differential Phase Contrast and Dark-Field Imaging
• Metrology Applications at Synchrotrons and XFELs
• Grating Fabrication
Diamond X-ray Optics for XFEL Experiments
• Diamond Zone Plates for XFELs
• Beam Splitter Gratings for Spectral Monitoring
• Ultra-Fast Pump-Probe Experiments