Hajime Ichikawa

testing at 1nm accuracy for sub-mm asphericity

This paper describes null interferometry at 1nm accuracy for testing aspherical surfaces of sub-mm deviation from the best fitting sphere. We have developed the two kinds of null compensators. The one is a “null lens” composed of almost perfect spherical surfaces and homogeneous glass. The other is a “zone plate” manufactured through the lithography process. The results of the two null testing were compared with the results by the ultra-precision CMM (Coordinate Measuring Machine). These totally different measurements differed only by an amount of 1.6nm rms. This result shows the accuracy of our null interferometry is almost 1nm rms.

Interferometry with Null Optics for Testing Aspherical Surfaces at 1nm Accuracy

This paper describes null interferometry at 1nm accuracy for testing aspherical surfaces of sub-mm deviation from the best fitting sphere. We have developed the two kinds of null compensators. The one was the null lens composed of almost “perfect” spherical surfaces and homogeneous glass. The other was the zone plate manufactured through the lithography process. The measurement results using these null compensators were compared with the results by the ultra-precision CMM (Coordinate Measuring Machine). These three measurements differed only by an amount of 1.6nm rms. This result proved the accuracy of our null interferometry was almost 1nm rms.

Design of and metrological results from a bent parabolic mirror

This article describes the successful design and fabrication of, and metrological results from, an elastically bent parabolic mirror. The mirror is equipped with a bending structure that allows the mirror to be bent meridionally to a parabolic shape. This bent parabolic mirror is the key component of the extremely high-quality monochromators designed for the SPring-8 figure-8 soft X-ray undulator and the 2.0 GeV high-brilliance synchrotron radiation source (VSX).