Soft-x-ray projection imaging with a 1:1 ring-field optic

Appl Opt. 1993 Dec 1;32(34):7072-8. doi: 10.1364/AO.32.007072.

Abstract

A molybdenum/silicon multilayer-coated 1:1 ring-field optic with a numerical aperture of 0.0835 is used to carry out soft-x-ray projection imaging with undulator radiation at 12.9 nm. An ideal optic of this type should be able to image 0.1-µm features with a contrast exceeding 90% at this wavelength. The useful resolution of our ring-field optic is experimentally found to be approximately 0.2 µm, probably because of the presence of substrate figuring errors.