X射线相衬成像光子筛

X-ray Zernike apodized photon sieves for phase-contrast microscopy

基于Zernike相衬成像原理和光瞳切趾原理,提出一种将相位板和切趾光子筛集成为一个相衬显微物镜的X射线相衬成像光子筛的设计方法.这种X射线相衬成像物镜可以实现生物体组织或者其他弱吸收材料的高分辨率和高衬度成像.通过优化光子筛透镜的衍射结构,可以抑制成像系统的点扩展函数的旁瓣和消除高阶衍射焦点,从而提高成像分辨率;另外,将光子筛透镜和变相板合为一体,克服了成像透镜和变相板难以对准的缺陷.以高斯切趾光子筛为例,实验验证了设计方法的可行性.

We present a kind of diffractive lens Zernike apodized photon sieves （ZAPS） whose structure is based on the combination of two concepts：apodized photon sieves and Zernike phase-contrast.Combined with the synchrotron light source,the ZAPS can be used as an objective for high-resolution phase-contrast X-ray microscopy in physical and life sciences.The ZAPS is a single optic unit that integrates the appropriate ±π/2 radians phase shift through selective zone placement shifts in an apodized photon sieve.The focusing properties of the ZAPS can be easily controlled by apodizing its pupil function.An apodized photon sieve with Gaussian pupil is fabricated by lithographic technique and shows that the side-lobes are significantly suppressed at the expense of slightly widening the width of the main lobe.