摘要
The Fourier transform(FT),a cornerstone of optical processing,enables rapid evaluation of fundamental mathematical operations,such as derivatives and integrals.Conventionally,a converging lens performs an optical FT in free space when light passes through it.The speed of the transformation is limited by the thickness and the focal length of the lens.By using the wave nature of surface plasmon polaritons(SPPs),here we demonstrate that the FT can be implemented in a planar configuration with a minimal propagation distance of around 10 mm,resulting in an increase of speed by four to five orders of magnitude.The photonic FT was tested by synthesizing intricate SPP waves with their Fourier components.The reduced dimensionality in the minuscule device allows the future development of an ultrafast on-chip photonic information processing platform for large-scale optical computing.
基金
supported by the National Natural Science Foundation of China 61427819
the Ministry of Science and Technology of China under National Basic Research Program of China(973)grant(No.2015CB352004)
the Discovery Early Career Researcher Award funded by the Australian Research Council under projects DE120102352 and DE130100954,respectively
support from the La Trobe Research Focus Area(RFA)of Understanding Diseases,theMelbourne Collaboration Grant and the Interdisciplinary Seed Fund through theMelbourne Materials Institute(MMI)
support from the Defence Science Institute,Australia
the Advanced Optics in Engineering Programme with Grant number 122-360-0009 from the Agency for Science,Technology and Research(A*STAR)and Singapore Ministry of Education Academic Research Fund Tier 3 with Grant number MOE2011-T3-1-005
the fellowship support from the A*STAR.
