Ion beam lithography for coherent x-ray optics application

We demonstrate the capabilities of ion-beam lithography (IBL) for the manufacturing of the X-ray refractive micro-optics. For the first time with the help of IBL, the hardest of current materials – diamond – was milled, and microscale diamond half-lenses were produced. Lenses have a rotationally parabolic profile with radii of parabola apexes in the range from 3 to 10 μm. As has been confirmed with SEM, the surface of produced lenses was free of low- and high-frequency modulations: figure errors of fabricated lenses were < 200 nm, while the surface roughness was estimated to be 30 nm. The optical performance of the lens was successfully tested at a third-generation synchrotron, where the lenses provided diffraction-limited focusing of X-ray radiation and demonstrated intensity profiles with Gaussian distributions at every measured longitudinal position (along the optical axis) downstream of the optics.