基于软X射线成像菲涅耳波带片精确光学传递函数的离焦图像恢复

摘要

高分辨率软X射线显微成像已被广泛用于获得样品的三维结构.然而,焦深的受限问题导致样品投影图像离焦模糊,严重影响图像质量.提出了一种基于菲涅尔波带片的光学传递函数离焦图像的恢复方法.利用这种恢复方法,恢复了Siemens star测试板的离焦图像.结果表明,基于光学传递函数的恢复方法能够去除因离焦而造成模糊现象并且恢复由离焦引起的离焦图像.而且,相关的模拟说明这种方法可以真正用于解决X射线显微成像中焦深受限问题,完成样品的三维成像.%High-resolution soft X-ray microscopy has been widely adopted for obtaining the three dimensional structure of physical objects.However,the limited depth of focus may cause sample defocusing and,subsequently,lead to blurring of images.A defocused image restoration method was proposed based on an optical transfer function (OTF) of a Fresnel zone plate (FZP).Using this restoration method the defocused image of Siemens star was restored.The results show that the restoration method based on OTF is capable of suppressing the blurring effect and restore defocus images caused by defocusing of the object.Furthermore,related simulations have been carried out to demonstrate the effectiveness of this method in overcoming the limitations to focal depth and accomplishing three dimensional imaging of samples.