Focusing of hard x-rays with monolithic two-dimensional multilayer Laue lenses: technical challenges and current status

Abstract

Hard X-ray microscopy is a powerful scientific tool capable of providing sub-10 nm spatial resolution imaging of material’s chemical composition and internal structure. Multilayer Laue Lenses (MLLs) have been developed and used for hard x-ray nanofocusing. MLLs are one dimensional X-ray diffractive optics fabricated through multilayer deposition and sectioning. An orthogonal alignment of two MLLs yields a point focus; 10 milli-degree orthogonality and sub-10 µm positioning accuracy along the beam direction is required to avoid astigmatism and achieve 10 nm focal spot size at 12 keV photon energy. Up-to-date, developed x-ray microscopy systems were equipped with eight degrees of nano-scale motion to perform full alignment of individual MLL optics. Bonding of two individual lenses together in pre-determined configuration significantly simplifies alignment process and makes them compatible with a more conventional Zone Plate – based microscopes. In this work, we give an overview of the existing bonding effort and present our approach to fabricate a monolithic 2D MLL optic.