极紫外宽带Mo/Si非周期多层膜偏振光学元件

研究了极紫外宽带多层膜偏振光学元件,包括反射式检偏器与透射式相移片。基于Mo/Si非周期多层膜结构,采用解析与数值优化相结合的方法进行了多层膜的设计;采用磁控溅射技术制备了多层膜。利用X射线衍射仪对非周期多层膜的结构进行了表征,利用德国BESSY-II同步辐射实验室的偏振测量仪对多层膜的偏振特性进行了测试。测量结果表明,在13~19 nm波段,s偏振分量的反射率高于15％;在15~17 nm波段,获得了37％的反射率。宽带多层膜同样可作为宽角偏振光学元件,在13.8~15.5 nm波段,宽带透射相移片的平均相移为41.7°。采用所研制的宽带多层膜相移片与检偏器,建立了宽带偏振分析系统,并对BESSY-II的UE56/1 PGM1光束线的偏振特性进行了系统研究。这种宽带多层膜偏振光学元件可以极大地简化极紫外偏振测量。

Broadband aperiodic Mo/Si multilayer polarization elements for EUV region

Broadband Mo/Si muhilayer polarization optical elements were developed for the extreme ultraviolet(EUV)region,including a reflective analyzer and a transmission phase retarder.These multilayers were designed by a combined analytical/numerical method based on an aperiodic stack.Then these aperiodic multilayers were fabricated using direct-current magnetron sputtering technology.The multilayer structures were measured by an X-ray Diffractometer(XRD)working at the Cuthe Program for New Century Excellent Talents in University(No.NCET-04-0376).Ka line,and the polarization response Was characterized by the polarimeter on the UE56/1-PGM1 beamline at BESSY-Ⅱ,in Berlin.The measured s-polarized reflectivity is higher than 15% over the 13～19 nm wavelength range,and nearly constant s-reflectivity,up to 37%,is observed over the 15～17nm wavelength range.Furthermore,these aperiodic multilayers show high s-reflectivity and polarization over a wide angular range at fixed wavelength.The measured phase shift is 41.7°over the 13.8～15.5 nm wavelength range.Using an aperiodic transmission phase retarder and a reflection analyzer,a complete broadband polarization analysis system was developed.The polarization properties of the synchrotron radiation from the beamline UE56/1 PGM1 at BESSY-Ⅱ were systematically characterized in the 12.7～15.5 nm wavelength range by this newly developed broadband polarization analysis system.This kind of broadband multilayer polarizing elements can be used in EUV polarization measurements and will greatly simplify experimental arrangements.