Recent Progress on Mirror-based Optical System for the 3rd and 4th Generation Synchrotron Radiation Sources
We developed precision figuring and figure testing methods to realize nano-focusing mirror devices for synchrotron radiation hard X-rays -. The fabricated mirrors were tested at the 1km-long beamline (BL29-XUL) of SPring-8, and confirmed to realize nearly diffraction-limited focusing with the spot size less than 30nm at 15keV X-ray .
In recent research, we constructed an extremely precise optical system for hard-x-ray single-nanometer focusing also at BL29-XUL of SPring-8. Precision multilayer mirrors were fabricated, tested, and installed into an optical system for the single-nanometer focusing with a novel phase compensator. In the phase compensator, an at-wavelength wavefront error sensing method based on x-ray interferometry and in situ phase-compensator mirror, which adaptively deforms with nanometer precision, were developed to satisfy the Rayleigh’s quarter wavelength criterion to achieve diffraction-limited focusing in a single-nanometer range.
The optical system developed was tested and confirmed to realize a spot size of approximately 7 x 8 nm2  - . I will talk about the ultimate focusing of the third generation synchrotron radiation x-rays at the size of single nanometer, together with a recent achievement of a microfocusing of Japanese X-ray free electron laser (SACLA), a mirror-based optical system satisfying Abbe’s sine condition for nano-imaging, and an adaptive optical system for a versatile x-ray microscopy.
These researches were partially supported by Grants-in-Aid for the Specially Promoted Research, for the scientific research (S), for promotion of XFEL research, for CREST project, and for the Global COE Program “Center of Excellence for Atomically Controlled Fabrication Technology” from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
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