Katsunobu Ueda

Machining high-precision mirrors using newly developed CNC machine

Summary An ultra precision CNC machine was develop for manufacturing high precision mirrors. The machine is capable of machining large aspheric mirrors up 650 mm in diameter and 250 mm in axial length. Laser interferometer feedback system, with 2.5 nm resolution, are incorporated in both X and Z slide motions. Using this machine, a concave mirror, made from an electroless nickel plated aluminum material, was finished by diamond turning. The mirror had a form accuracy of less than 0.1 μm P-V, and a 2 nm Ra surface roughness.

Fabrication of micromechanical and optical components by ultraprecision cutting

Micro mechanical parts and optical parts are fabricated through ultra precision cutting technique. The precision cutting technique has been considered to be inappropriate for micro parts fabrication of the micrometer order. Our ultra precision cutting technique with sub-micrometer cutting depth made it possible to fabricate 3D micro mechanical parts and micro optical parts. Following micro mechanical parts are fabricated: 10 micrometer shaft by lathe machining, 100 micrometer screw with 20 micrometer pitch thread, and 50 micrometer thickness lever made by stainless steel. Also it was able to fabricate micro optical parts such as holographic optical element with sawtooth cross section and pitch of 3 micrometer. The fabrication was carried out with newly developed ultra precision machine tool with X, Y, Z linear axis and one rotational axis using single crystalline diamond cutting tool. Those linear axis are controlled through hologram scale with 1 nm resolution. The fabrication process by precision cutting has proved to be faster and more precise compared to the lithography and etching method.

A Soft X-Ray Microscope Using an Imaging Detector

An X-ray microscope, consisting of a Wolter-type mirror and an imaging detector, was constructed. The configuration of the mirror was optimized by the ray-tracing procedure. The resolution of the imaging detector was estimated to be better than 1 µm from the spot diagram of the electron lenses. A photocathode made of a CsI layer as a photoemitter and a SiNx membrane as a support for the CsI layer is presented. The fundamental performance of the X-ray microscope has been evaluated, and its resolution has been estimated to be better than 2 µm.

X-ray multilayer mirrors for grazing incidence

Material pairs of Re/Al, Re/Mg, Re/B, Pt/B, and Pt/C were selected for grazing incidence multilayer mirrors having a high reflectance for about 1 nm wavelength x ray. The multilayers were fabricated by electron beam deposition and Knudsen cell heating deposition, and were evaluated as to whether or not they had a periodic structure and stability in atmospheric storage. A periodic structure was observed in the transmission electron micrograph for the Pt/C and the Re/B multilayers, although the Re/B multilayer was found to have a decay after a month of fabrication. This decay was caused by the formation of an Re oxide as judged from the x-ray photoelectron spectroscopy analysis.