New applications of optics for short wavelengths
In recent years, optics development has increasingly focused on optical components for ever shorter wavelengths. This trend is based on the one hand on the demand to increase the resolving power of optical systems and on the other hand on the availability of powerful beam sources in the extreme ultraviolet (EUV) and soft X-ray range.
In addition to EUV lithography (λ = 13.5 nm), outstanding applications of EUV and X-ray optics include: applications in astronomy, beamline optics for synchrotrons, optics for X-ray lasers and, in the future, XFELs. There is also great potential for microscopy in the so-called water window (λ = 2.4 nm ... 4.4 nm). In this spectral range, many biological samples are transparent and thus particularly easily accessible for investigations. The extremely short wavelengths enable unprecedented resolutions and thus completely new examination methods in biology and medicine. Reflection values of 5.2 % at 2.48 nm and 20 % at 3.1 nm were achieved by multilayer systems based on chromium, vanadium and scandium.