Rainbow light trapping in plasmonic devices allows for field enhancement of multiple wavelengths within a single device.However,many of these devices lack precise control over spatial and spectral enhancement profiles...Rainbow light trapping in plasmonic devices allows for field enhancement of multiple wavelengths within a single device.However,many of these devices lack precise control over spatial and spectral enhancement profiles and cannot provide extremely high localised field strengths.Here we present a versatile,analytical design paradigm for rainbow trapping in nanogroove arrays by utilising both the groove-width and groove-length as tuning parameters.We couple this design technique with fabrication through multilayer thin-film deposition and focused ion beam milling,which enables the realisation of unprecedented feature sizes down to 5 nm and corresponding extreme normalised local field enhancements up to 103.We demonstrate rainbow trapping within the devices through hyperspectral microscopy and show agreement between the experimental results and simulation.The combination of expeditious design and precise fabrication underpins the implementation of these nanogroove arrays for manifold applications in sensing and nanoscale optics.展开更多
基金supported by the Ontario Research Fund-Research Excellence programmethe Natural Sciences and Engineering Research Council of Canada,the Canadian Research Foundation,the University of Toronto+2 种基金supported by the Mitacs Globalink programme and the micro-nanotechnology award provided by CMC Microsystemssupported in part by the Berkeley Synchrotron Infrared Structural BioImaging(BSISB)Program under its DOE Office of Science Contract No.DEAC02-05CH11231supported by the Office of Science,Office of Basic Energy Sciences,of the U.S.Department of Energy under contract No.DE-AC02-05CH11231.
文摘Rainbow light trapping in plasmonic devices allows for field enhancement of multiple wavelengths within a single device.However,many of these devices lack precise control over spatial and spectral enhancement profiles and cannot provide extremely high localised field strengths.Here we present a versatile,analytical design paradigm for rainbow trapping in nanogroove arrays by utilising both the groove-width and groove-length as tuning parameters.We couple this design technique with fabrication through multilayer thin-film deposition and focused ion beam milling,which enables the realisation of unprecedented feature sizes down to 5 nm and corresponding extreme normalised local field enhancements up to 103.We demonstrate rainbow trapping within the devices through hyperspectral microscopy and show agreement between the experimental results and simulation.The combination of expeditious design and precise fabrication underpins the implementation of these nanogroove arrays for manifold applications in sensing and nanoscale optics.
