Achromatic Talbot lithography(ATL)with high resolution has been demonstrated to be an excellent technique for large area periodic nano-fabrication.In this work,the uniformity of pattern distribution in ATL was studied...Achromatic Talbot lithography(ATL)with high resolution has been demonstrated to be an excellent technique for large area periodic nano-fabrication.In this work,the uniformity of pattern distribution in ATL was studied in detail.Two ATL transmission masks with^50%duty cycle in a square lattice were illuminated by a spatial coherent broadband extreme ultraviolet beam with a relative bandwidth of 2.38%.Nonuniform dot size distribution was observed by experiments and finite-difference time-domain simulations.The sum of the two kinds of diffraction patterns,with different lattice directions(45°rotated)and different intensity distributions,results in the final nonuniform pattern distribution.展开更多
High-resolution lens-coupled indirect X-ray scintillator imagers are required by many imaging applications.However,the severe weakening of image details prevents its further performance improvement.Through our researc...High-resolution lens-coupled indirect X-ray scintillator imagers are required by many imaging applications.However,the severe weakening of image details prevents its further performance improvement.Through our research,this image degradation is attributed to the broadband loss of the high-spatial-frequency information caused by the high refractive index.A technique known as high-spatial-frequency spectrum enhanced reconstruction is thus proposed to retrieve this information.A two-dimensional high-density array is covered on the scintillator’s exit surface and operates as an encoder based on which high-frequency information can be shifted to the low-frequency region to improve the signal-to-noise ratio.The experimental results show that the middle-high-frequency signal intensities can be increased by an order of magnitude or more,up to^50 times.Therefore,the image details can be effectively enhanced to break through the performance bottleneck of such widely used X-ray imagers for synchrotron radiation facilities or tabletop X-ray tubes.展开更多
基金supported by the National Key R&D Program of China(No.2017YFA0206001)the National Natural Science Foundation of China(Nos.11505275,51705369,11275255,11475251,and 11875314)the Shanghai Science and Technology Commission Research Projects(No.17JC1400802)
文摘Achromatic Talbot lithography(ATL)with high resolution has been demonstrated to be an excellent technique for large area periodic nano-fabrication.In this work,the uniformity of pattern distribution in ATL was studied in detail.Two ATL transmission masks with^50%duty cycle in a square lattice were illuminated by a spatial coherent broadband extreme ultraviolet beam with a relative bandwidth of 2.38%.Nonuniform dot size distribution was observed by experiments and finite-difference time-domain simulations.The sum of the two kinds of diffraction patterns,with different lattice directions(45°rotated)and different intensity distributions,results in the final nonuniform pattern distribution.
基金National Key Research and Development Program of China(2017YFA0403400,2016YFA0401302)Science and Technology Commission of Shanghai Municipality(17JC1400802)+1 种基金National Natural Science Foundation of China(11775291)Shanghai Giant Science Center RD Project。
文摘High-resolution lens-coupled indirect X-ray scintillator imagers are required by many imaging applications.However,the severe weakening of image details prevents its further performance improvement.Through our research,this image degradation is attributed to the broadband loss of the high-spatial-frequency information caused by the high refractive index.A technique known as high-spatial-frequency spectrum enhanced reconstruction is thus proposed to retrieve this information.A two-dimensional high-density array is covered on the scintillator’s exit surface and operates as an encoder based on which high-frequency information can be shifted to the low-frequency region to improve the signal-to-noise ratio.The experimental results show that the middle-high-frequency signal intensities can be increased by an order of magnitude or more,up to^50 times.Therefore,the image details can be effectively enhanced to break through the performance bottleneck of such widely used X-ray imagers for synchrotron radiation facilities or tabletop X-ray tubes.
