Current research activities in the field of multilayer for EUV, soft x-ray and x-rays in IPOE

摘要

The present status of studies on EUV, soft x-ray and x-ray multilayer in the Institute of Precision Optical Engineering (IPOE) is briefly reviewed. With the aim of realizing a Mach-Zender interferometer working at 13.9nm, we have developed a semitransparent beam splitter with multilayer deposited on the back side of a silicon nitride membrane. On the basis of the experimental optical properties of the beam splitter, design has been performed to define the multilayer structure that provides the highest product of reflectivity and transmission. Optimized Mo/Si multilayer has been successfully deposited on the back side of a silicon nitride membrane by use of the magnetron sputtering. Measurements by means of a reflectometer in Beijing Synchrotron Radiation Facility at 13.9nm and at an angle of 7.2° provide a reflectivity of 20% and a transmission of 22%. Such a beam splitter has been used for X-ray Mach-Zender interferometer at 13.9nm. The broadband multilayer analyzer in the range between 12.4nm and 20nm is designed, and made which can deviate the Quasi-Brewster's angle several degree and show very high polarization. The main feature of our design approach is the use of an analytical solution as a starting point for direct computer search, and the desired results can be given in a reasonable time. The method can be applied in different spectral range for suitable material combination. Supermirrors with broad angular band working at different wavelength such as Cu Kcc line are designed, manufactured and measured. The results show that the performance of the supermirrors is in agreement with designed data.