%0 Journal Article %T Designing optimal nanofocusing with a gradient hyperlens %A Shen, Lian %A Prokopeva, Ludmila J. %A Chen, Hongsheng %A Kildishev, Alexander V. %J Nanophotonics %V 7 %N 2 %P 479-487 %@ 2192-8614 %D 2017-11-09 %I De Gruyter %~ DeepDyve