Monolithic Fabry-Perot Structure For Soft X-Rays

The design, fabrication, and preliminary characterization and test results for reflection Fabry-Perot etalon structures operating with soft X-rays is described. The etalons were designed for maximum performance near normal incidence and for 125 A radiation, close to the silicon L absorption edge. The structures were fabricated with a dc sputtering technique and consist of two molybdenum/silicon multilayers separated by a silicon spacer. The samples have been characterized by several complimentary methods and reflectivity measurements have been made using synchrotron radiation. The reflectance has a sharp maximum (27%) for 124 A light incident at 10 o from normal. Interference effects between the two reflectors, through the spacer, are clearly demonstrated.