Proceedings Article | 3 October 2022
KEYWORDS: Optical components, X-rays, X-ray optics, Nanolithography, Nanostructuring, Zone plates, X-ray microscopy, X-ray lasers, X-ray diffraction, Wavefronts
At XRnanotech, which is a spin-off company from the Paul Scherrer Institut in Switzerland, we use different nanolithography approaches to structure optical elements down to the single-digit nanometer scale. We use electron-beam nanolithography, two-photon polymerization, direct laser writing and combinations of these techniques to offer outstanding solutions mainly in the field of X-ray optics. Such nanostructured optical elements enable experiments at many large-scale research facilities and are a hot topic in many industries. Our goal is to push the limits of diffractive optics by continuously improving the resolution and efficiency.
X-rays are of great interest as these beams offer elemental and chemical sensitivity along with high penetration depth. They represent excellent probes for research and investigation of matter. However, they are challenging to focus using standard refractive optical elements. This is necessary as the ongoing development of accelerator-based photon sources like synchrotrons or X-ray free-electron lasers (XFELs) led to a strong increase in X-ray brilliance over the last decades and enabled ever-new experimental techniques with unprecedented spatial, temporal and spectral resolution. Apart from X-rays, we pursue applications of diffractive optics from infrared to the ultraviolet by exploring new fabrication methods, materials, processes, and designs.
We exploit the fact that diffractive optics have a fundamental advantage over other kinds of optical elements like mirrors and refractive lenses, which is the possibility to precisely control and manipulate the optical wave front. This allows realizing complex optical functionalities like beam-shaping optics for X-ray microscopes, spiral zone plates for generating beams with an orbital angular momentum, off axis zone plates that combine microscopy and spectroscopy, beam-splitting zone plates for focusing and beam-splitting as well as achromatic X-ray optical elements [1-6].
In this contribution, we will highlight the latest developments in fabricating diffractive optical elements at XRnanotech aiming at best resolution, efficiency and optical functionality.
[1] P R Ribič et al. Phys. Rev. X 24 p. 296 (2018). [2] F. Döring et al. Optica 7 (8), 1007-1014 (2020).
[3] B Rösner, et al., Optics Express 25 (2017). [4] I. Vartiainen, et al., Optics Express 23 (2015).
[5] B. Rösner et al. Optica 7 (11), 1602-1608 (2020). [6] A. Kubec et al. Nat. Com. (2022).
