Design,fabrication and test of x ray freestanding transmission qratinqs
自支撑透射光栅的设计、制作和测试

The diffraction efficiency of freestanding x ray transmission gratings is discussed in relation to the wavelength and grating period using both scalar diffraction theory and rigorous coupled wave analysis,and the grating design is accordingly optimized.A gold freestanding x ray transmission grating with period of 300 nm,line/period ratio of 0.55,thickness of 200 nm a size of 1 mm×1 mm and fractional grating area of 65%is fabricated.The absolute diffraction efficiency of the fabricated grating was tested at the National Synchrotron Radiation Laboratory in the wavelength region of 5.5-38 nm.The test result shows that the grating has a maximum efficiency of nearly 10%.The grating also shows a stable diffraction efficiency in the wavelength region from 15 nm to 35 nm.