水窗波段反射式偏振光学元件的设计和制作

水窗波段是软X射线进行生物活细胞显微成像的最佳波段，因此对于水窗波段偏振光学元件的研究有着非常重要的意义。用菲涅耳公式计算出在水窗波段内不同材料组合对应不同波长的最大反射率，模拟分析了多层膜周期和表界面粗糙度对多层膜偏振光学元件性能的影响。用超高真空磁控溅射镀膜设备，制作出2．40nm、3．00nm和4．30nm波长处W／B4C多层膜偏振元件，并用X射线衍射仪对元件的周期厚度进行了测量，得到的测量结果与设计值偏差很小，可以进行实际应用。为水窗波段反射式偏振光学元件的研究提供了理论依据，同时也为相应偏振光学元件的制备确定了合适的工艺参量。

Design and Fabrication the Polarizing Elements of Reflection Multilayer Film in Water Window Wave Band

Water window is a special wave band for microscopy in soft X-ray range,which makes the research in water window polarization great significance.With Fresnel formula,the maximum reflectivity is calculated for different materials at corresponding wavelength in water window,the influence of the multilayers' periods and surface roughness on the element performance is analysed.Three W/B_4C multilayers are produced for polarizing elements in special wavelengths 2.40 nm,3.00 nm and 4.30 nm based on ultrahigh vacuum magnetron sputtering equipment,the periodic thickness of elements by X-ray diffraction instrument is measured.The results with little windage prove practical.The work is essential in the study of polarizing elements of reflection multilayeres in water window which provides the theory and the suitable parameters for mutilayeres fabrication.