The Research Of Multilayer Polarizing Components In Extreme Ultraviolet And Soft X-Ray

Polarized light in the extreme ultraviolet (EUV) and soft X-ray range is a valuable tool in the investigation of magnetic materials and magneto-optical effects, measurement of Faraday and Kerr effects, and polarization analysis of the synchrotron radiation. These polarizing measurements could be used in the study of a wide range of phenomena in biology, chemistry, physics, and material science. Such a demand increases the development of the polarizing components based on multilayer interference, which are the key optical elements in the measurement of the polarization for the synchrotron radiation. The multilayer polarizers, analyzers and phase retarders using different material combinations have been developed in American, European and Japanese groups. The polarization investigation in China has not been performed because of lacking the relevant polarizing components.The criteria and method for optimum polarization of EUV and soft x-ray multilayer polarizing optical components are presented. The Cr/Sc, Cr/C, La/B₄C, Mo/Y, Mo/Si reflective analyzers and Mo/Y, Mo/Si transmission polarizers and phase retarders are fabricated using direct current magnetron sputtering. These optical elements can provide full control of the polarization of the incident light in x-ray spectroscopy. The Cr/C and Mo/Si reflective analyzers are used in the on-line alignment of the polarimeter in Beijing Synchrotron Radiation Facility (BSRF), and the polarization state of the beam line 3W1B are measured.The traditional periodic multilayer polarizing components are effective over a very small wavelength range, and the narrow band wavelength and angular properties may be disadvantageous for some studies. In order to overcome this, the aperiodic multilayer structures have been developed based on a combination of analytical and numerical method, which is used in the design of supermirror in the hard X-ray range. The broadband Mo/Si and Mo/Y multilayer analyzers are deposited on the super-polished silicon wafer, and the broadband Mo/Si multilayer phase retarders are made using direct current magnetron sputtering on silicon nitride membrane. X-ray...