Recently, individual reduced-symmetry metal nanostructures and their plasmonic properties have been studied extensively. However, little attention has been paid to the approach to fabricating ordered reduced-symmetry ...Recently, individual reduced-symmetry metal nanostructures and their plasmonic properties have been studied extensively. However, little attention has been paid to the approach to fabricating ordered reduced-symmetry metal nanostructure arrays. In this paper, a novel perforated silver nanocap array with high surface-enhanced Raman scattering （SERS） activity and fluorescence suppression is reported. The array is fabricated by electron beam evaporating Ag onto the perforated barrier layer side of a hard anodization （HA） anodic aluminum oxide （AAO） template. The morphology and optical property of the perforated silver nanocap array are characterized by an atomic force microscope （AFM）, a scanning electron microscope （SEM）, and absorption spectra. The results of SERS measurements reveal that the perforated silver nanocap array offers high SERS activity and fluorescence suppression compared with an imperforated silver nanocap array.展开更多
The development of hybrid optics/microwave communication systems puts forward a new requirement for beam splitters to efficiently transmit microwave signals and simultaneously reflect optical signals. Owing to mechani...The development of hybrid optics/microwave communication systems puts forward a new requirement for beam splitters to efficiently transmit microwave signals and simultaneously reflect optical signals. Owing to mechanical constraints, the physical thickness of beam splitters is of the order of tens of millimeters. The corresponding electrical thickness has the same order of magnitude as microwave wavelengths, and the resulting multi-beam interference effect significantly reduces the microwave transmittance, impacting the beam splitting quality.This study presents a new optics/microwave beam splitter based on the ability of the frequency selective surface(FSS) to shape the resonant curve. A beam splitter sample,whose physical thickness and substrate material are 20 mm and quartz glass, respectively, is designed, simulated, fabricated, and characterized to validate the feasibility of this strategy. The measured results show that the minimum microwave transmittance between 35 and 36.5 GHz with an incidence angle of 45° under TE polarization is 86.43%, and the mean value of the reflectance spectra from 450 to 900 nm and that from 7.7 to 10.5 μm both exceed 96%. This FSS-based optics/microwave beam splitter is expected to play a key role in hybrid optics/microwave communication systems.展开更多
In this work,a simple fabrication method of germanium-based metasurfaces is proposed,where the deposited Al_(2)O_(3) layer with high selectivity is chosen as the hard mask and retained after the dry etching process.Th...In this work,a simple fabrication method of germanium-based metasurfaces is proposed,where the deposited Al_(2)O_(3) layer with high selectivity is chosen as the hard mask and retained after the dry etching process.The simulation and experimental characterization results verify the feasibility of the fabrication method.The experimental study on the fabrication methods of germanium-based metasurfaces is very significant as the meta-atoms with a higher refractive index can achieve 0 to 2πtransmission phase variation with a smaller period under the same thickness-to-period ratio,which is consistent with the requirement of the period miniaturization in some cases.展开更多
基金Project supported by the Industry Key Technologies R & D Project in Shaanxi Province of China (Grant No. 2012K07-19)
文摘Recently, individual reduced-symmetry metal nanostructures and their plasmonic properties have been studied extensively. However, little attention has been paid to the approach to fabricating ordered reduced-symmetry metal nanostructure arrays. In this paper, a novel perforated silver nanocap array with high surface-enhanced Raman scattering （SERS） activity and fluorescence suppression is reported. The array is fabricated by electron beam evaporating Ag onto the perforated barrier layer side of a hard anodization （HA） anodic aluminum oxide （AAO） template. The morphology and optical property of the perforated silver nanocap array are characterized by an atomic force microscope （AFM）, a scanning electron microscope （SEM）, and absorption spectra. The results of SERS measurements reveal that the perforated silver nanocap array offers high SERS activity and fluorescence suppression compared with an imperforated silver nanocap array.
基金supported by the National Natural Science Foundation of China (No. 61901437)。
文摘The development of hybrid optics/microwave communication systems puts forward a new requirement for beam splitters to efficiently transmit microwave signals and simultaneously reflect optical signals. Owing to mechanical constraints, the physical thickness of beam splitters is of the order of tens of millimeters. The corresponding electrical thickness has the same order of magnitude as microwave wavelengths, and the resulting multi-beam interference effect significantly reduces the microwave transmittance, impacting the beam splitting quality.This study presents a new optics/microwave beam splitter based on the ability of the frequency selective surface(FSS) to shape the resonant curve. A beam splitter sample,whose physical thickness and substrate material are 20 mm and quartz glass, respectively, is designed, simulated, fabricated, and characterized to validate the feasibility of this strategy. The measured results show that the minimum microwave transmittance between 35 and 36.5 GHz with an incidence angle of 45° under TE polarization is 86.43%, and the mean value of the reflectance spectra from 450 to 900 nm and that from 7.7 to 10.5 μm both exceed 96%. This FSS-based optics/microwave beam splitter is expected to play a key role in hybrid optics/microwave communication systems.
基金supported by the National Natural Science Foundation of China(No.12204478).
文摘In this work,a simple fabrication method of germanium-based metasurfaces is proposed,where the deposited Al_(2)O_(3) layer with high selectivity is chosen as the hard mask and retained after the dry etching process.The simulation and experimental characterization results verify the feasibility of the fabrication method.The experimental study on the fabrication methods of germanium-based metasurfaces is very significant as the meta-atoms with a higher refractive index can achieve 0 to 2πtransmission phase variation with a smaller period under the same thickness-to-period ratio,which is consistent with the requirement of the period miniaturization in some cases.
