Metamaterials composed of metallic antennae arrays are used as they possess extraordinary optical transmission(EOT)in the terahertz(THz)region,whereby a giant forward light propagation can be created using constructiv...Metamaterials composed of metallic antennae arrays are used as they possess extraordinary optical transmission(EOT)in the terahertz(THz)region,whereby a giant forward light propagation can be created using constructive interference of tunneling surface plasmonic waves.However,numerous applications of THz meta-devices demand an active manipula-tion of the THz beam in free space.Although some studies have been carried out to control the EOT for the THz region,few of these are based upon electrical modulation of the EOT phenomenon,and novel strategies are required for act-ively and dynamically reconfigurable EOT meta-devices.In this work,we experimentally present that the EOT resonance can be coupled to optically reconfigurable chalcogenide metamaterials which offers a reversible all-optical control of the THz light.A modulation efficiency of 88%in transmission at 0.85 THz is experimentally observed using the EOT metama-terials,which is composed of a gold(Au)circular aperture array sitting on a non-volatile chalcogenide phase change ma-terial(Ge2Sb2Te5)film.This comes up with a robust and ultrafast reconfigurable EOT over 20 times of switching,excited by a nanosecond pulsed laser.The measured data have a good agreement with finite-element-method numerical simula-tion.This work promises THz modulators with significant on/off ratios and fast speeds.展开更多
We fabricate a series of periodic arrays of subwavelength square and rectangular air holes on gold films, and measure the transmission spectra of these metallic nanostructures. By changing some geometrical and physica...We fabricate a series of periodic arrays of subwavelength square and rectangular air holes on gold films, and measure the transmission spectra of these metallic nanostructures. By changing some geometrical and physical parameters, such as array period, air hole size and shape, and the incident light polarization, we verify that both global surface plasmon resonance and localized waveguide mode resonance are influential on enhancing the transmission of light through nanostructured metal films. These two resonances induce different behaviours of transmission peak shift. The transmission through the rectangular air-hole structures exhibits an obvious polarization effect dependent on the morphology. Numerical simulations are also made by a plane-wave transfer-matrix method and in good consistency with the experimental results.展开更多
In this paper we study the extraordinary optical transmission of one-dimensional multi-slits in an ideal metal film.The transmissivity is calculated as a function of various structural parameters.The transmissivity os...In this paper we study the extraordinary optical transmission of one-dimensional multi-slits in an ideal metal film.The transmissivity is calculated as a function of various structural parameters.The transmissivity oscillates,with the period being just the light wavelength,as a function of the spacing between slits.As the number of slits increases,the transmissivity varies in one of three ways.It can increase,attenuate,or remain basically unchanged,depending on the spacing between slits.Each way is in an oscillatory manner.The slit interaction responsible for the oscillating transmission strength that depends on slit spacing is the subject of more detailed investigation.The interaction most intuitively manifests as a current distribution in the metal surface between slits.We find that this current is attenuated in an oscillating fashion from the slit corners to the center of the region between two adjacent slits,and we present a mathematical expression for its waveform.展开更多
We investigate both experimentally and numerically a complex structure, where ＇face-to-face＇ Helmholtz resonance cavities （HRCs） are introduced to construct a one-dimensional acoustic grating. In this system, pair...We investigate both experimentally and numerically a complex structure, where ＇face-to-face＇ Helmholtz resonance cavities （HRCs） are introduced to construct a one-dimensional acoustic grating. In this system, pairs of HRCs can intensely couple with each other in two forms： a bonding state and an anti-bonding state, analogous to the character of hydrogen molecule with two atoms due to the interference of wave functions of sound among the acoustic local-resonating structures. The bonding state is a ＇bright＇ state that interferes with the Fabry-Pbrot resonance mode, thereby causing this state to break up into two modes as the splitting of the extraordinary acoustic transmission peak. On the contrary, the anti-bonding state is a ＇dark＇ state in which the resonance mode remains entirely localized within the HRCs, and has no contribution to the acoustic transmission.展开更多
Extraordinary acoustic transmission （EAT） has been investigated in a tunable bull＇s eye structure. We demonstrate that the transmission coefficient of acoustic waves can be modulated by a grating structure. When th...Extraordinary acoustic transmission （EAT） has been investigated in a tunable bull＇s eye structure. We demonstrate that the transmission coefficient of acoustic waves can be modulated by a grating structure. When the grating is located at a distance of 0.5 mm from the base plate, the acoustic transmission shows an 8.77-fold enhancement compared to that by using a traditional bull＇s eye structure. When the distance increases to 1.5 mm, the transmission approaches zero, indicating a total reflection. Thus, we can make an efficient modulation of acoustic transmission from 0 to 877%. The EAT effects have been ascribed to the coupling of structure-induced resonance with the diffractive wave and the waveguide modes, as well as the Fabry-Perot resonances. As a potential application, the modulation of far-field collimation is illustrated in the proposed bull＇s eye structure.展开更多
We studied numerically the temperature dependent extraordinary terahertz transmission through niobium nitride(NbN) film perforated with subwavelength spindle-like apertures. Both the resonant frequency and intensity o...We studied numerically the temperature dependent extraordinary terahertz transmission through niobium nitride(NbN) film perforated with subwavelength spindle-like apertures. Both the resonant frequency and intensity of extraordinary terahertz transmission peaks can be greatly modified by the transition of NbN film from the normal state to the superconducting state. An enhancement of the(±1, 0) NbN/magnesium oxide(MgO) peak intensity as high as 200% is demonstrated due to the combined contribution of both the superconducting transition and the excitation of localized surface plasmons(LSPs) around the apertures. The extraordinary terahertz transmission through spindle-like hole arrays patterned on the NbN film can pave the way for us to explore novel active tuning devices.展开更多
Metallic gratings with narrow slits can lead to special optical properties such as strongly enhancing the trans- mission and considerably strengthening the polarized effect. A narrow-band filter suitable for applicati...Metallic gratings with narrow slits can lead to special optical properties such as strongly enhancing the trans- mission and considerably strengthening the polarized effect. A narrow-band filter suitable for application in optical communication is designed by sandwiching a metallic grating between two identical dielectric films. The maximum transmission can reach 96% after optimizing the parameters of films and grating at a central wavelength of 1053 nm. It is the first time, to our knowledge, that such high transmission has been reported since the discovery of the extraordinarily high transmission through periodic holes or slits; moreover, the extremely polarized effect is also found in P mode of this symmetric grating.展开更多
We experimentally detect high-refractive-index media (n > 1.5) using a surface plasmon resonance (SPR) sensor with a diffraction grating. While SPR sensors are generally based on the attenuated total reflection met...We experimentally detect high-refractive-index media (n > 1.5) using a surface plasmon resonance (SPR) sensor with a diffraction grating. While SPR sensors are generally based on the attenuated total reflection method using metal films, here, we focus on a method using a diffraction grating, which can detect relatively higher refractive-index media and is suitable for device miniaturization. In this study, we used the rigorous coupled-wave analysis method to simulate the dependence of the reflectance on an incident angle for media with refractive index values up to 1.700. In the experiment, a medium (n = 1.660 - 1.700) was successfully detected using this grating. Under the conditions of the grating (period: 600 nm, Au thickness: 40 nm) using a red laser (λ: 635 nm), a sharp decline in the reflectance and a rise in the transmittance at certain angles were confirmed, demonstrating the extraordinary transmission enabled by SPR. Because excitation angles changed with changes in the refractive index, we concluded that this method can be applied to sensors that detect high-refractive-index media.展开更多
We show that a metasurface composed of a subwavelength metallic slit array embedded in an asymmetric dielectric environment can exhibit either diffraction （EOD）. The cascaded refractive extraordinary optical transmi...We show that a metasurface composed of a subwavelength metallic slit array embedded in an asymmetric dielectric environment can exhibit either diffraction （EOD）. The cascaded refractive extraordinary optical transmission （EOT） or extraordinary optical indices of the dielectrics can leverage multiple decaying passages into variant subsections with different diffraction order combinations according to the diffraction order chart in the k-vector space, providing a flexible by changing the wavevector of the efficiencies can be enhanced to near or EOD in a single tional metasurface onstrated. Our findings incident light. As a result, either the unity by the excitation of the localized provide a convenient way components on a single planar device.展开更多
Electrochemical （EC） reactions play vital roles in many disciplines, and its molecular-level understanding is highly desired, in particular under reactions. The vibration spectroscopy is a powerful in situ technique...Electrochemical （EC） reactions play vital roles in many disciplines, and its molecular-level understanding is highly desired, in particular under reactions. The vibration spectroscopy is a powerful in situ technique for chemical analysis, yet its application to EC reactions is hindered by the strong attenuation of infrared （IR） light in both electrodes and electrolytes. Here we demonstrate that by incorporating appropriate sub-wavelength plasmonic structures at the metal electrode, the IR field at the EC interface can be greatly enhanced via the excitation of surface plasmon. This scheme facilitates in situ vibrational spectroscopic studies, especially using the surface-specific sum-frequency generation technique.展开更多
The extraordinary optical transmission （EOT） phenomenon of nano-periodic aperture array in metallic film has been widely investigated and used in biosensors. The surface plasmon resonance and cavity mode in some per...The extraordinary optical transmission （EOT） phenomenon of nano-periodic aperture array in metallic film has been widely investigated and used in biosensors. The surface plasmon resonance and cavity mode in some periodic nanos- tructures, such as nanohole and nanoslit, cause EOTs at certain wavelengths. This resonance wavelength is sensitive to the refractive index on the surface of periodic nanostructures. Therefore, the metallic nanostructures are expected to be good sensing elements. The sensing performances of gold nanoslit arrays are experimentally and theoretically investigated. Three-dimensional finite difference time domain （FDTD） simulations are utilized to explore their transmission spectra and steady-state field intensity distributions. The electron beam evaporation, electron beam lithography, and ion milling are applied to the gold nanoslit arrays with different widths and periods. The sensing performances of the gold nanoslit ar- ray are characterized via transmission spectra in four kinds of refractive index samples. The highest sensitivity reaches 726 nm/RIU when the width of the gold nanoslit array is 38.5 nm.展开更多
We studied the infrared transmission properties of gold films on ordered two-dimensional nonclose- packed polystyrene （PS） colloidal crystal. The gold films consist of gold half-shells on the PS spheres and gold fil...We studied the infrared transmission properties of gold films on ordered two-dimensional nonclose- packed polystyrene （PS） colloidal crystal. The gold films consist of gold half-shells on the PS spheres and gold film with 2D arrays of holes on the glass substrate. An extraordinary optical transmission phenomenon could be found in such a structure. Simulations with the finite-difference time-domain method were also employed to get the transmission spectra and electric field distribution. The transmission response of the samples can be adjusted by controlling the thickness of the gold films. Angle-resolved measurements were performed using polarized light to obtain more information about the surface plasmon polariton resonances of the gold films. As the angle changes, the transmission spectra change a lot. The transmission spectra of p-polarized light have quite different properties compared to those of s-polarized light.展开更多
Reconfigurable metamaterials significantly expand the application scenarios and operating frequency range of metamaterials,making them promising candidates for use in smart tunable device.Here,we propose and experimen...Reconfigurable metamaterials significantly expand the application scenarios and operating frequency range of metamaterials,making them promising candidates for use in smart tunable device.Here,we propose and experimentally demonstrate that integrating metamaterial design principles with the intrinsic features of natural materials can engineer thermal smart metadevices.Tunable extraordinary optical transmission like(EOT-like)phenomena have been achieved in the microwave regime using shape memory alloy(SMA).The strongly localized fields generated by designed metadevices,combined with the intense interference of incident waves,enhance transmission through subwavelength apertures.Leveraging the temperature-responsive properties of SMA,the morphology of the metadevice can be recontructed,thereby modifying its response to electromagnetic waves.The experiments demonstrated control over the operating frequency and transmission amplitude of EOT-like behavior,achieving a maximum transmission enhancement factor of 126.Furthermore,the metadevices with modular design enable the realization of multiple functions with independent control have been demonstrated.The proposed SMA-based metamaterials offer advantages in terms of miniaturization,easy processing,and high design flexibility.They may have potential applications in microwave devices requiring temperature control,such as sensing and monitoring.展开更多
Since the discovery of the extraordinary optical transmission phenomenon,nanohole arrays have attracted much attention and been widely applied in sensing.However,their typical fabrication process,utilizing photolithog...Since the discovery of the extraordinary optical transmission phenomenon,nanohole arrays have attracted much attention and been widely applied in sensing.However,their typical fabrication process,utilizing photolithographic top-down manufacturing technologies,has intrinsic drawbacks including the high costs,time consumption,small footprint,and low throughput.This study presented a low-cost,high-throughput,and scalable method for fabricating centimeter-scale(1×2 cm2)nanohole arrays using the improved nanosphere lithography.The large-scale close-packed polystyrene monolayers obtained by the hemispherical-depression-assisted self-assembly method were employed as colloidal masks for the nanosphere lithography,and the nanohole diameter was tuned from 233 nm to 346 nm with a fixed period of 420 nm via plasma etching.The optical properties and sensing performance of the nanohole arrays were investigated,and two transmission dips were observed due to the resonant coupling of plasmonic modes.Both dips were found to be sensitive to the surrounding environment,and the maximum bulk refractive index sensitivity was up to 162.1 nm/RIU with a 233 nm hole diameter.This study offered a promising approach for fabricating large-scale highly ordered nanohole arrays with various periods and nanohole diameters that could be used for the development of low-cost and high-throughput on-chip plasmonic sensors.展开更多
文摘Metamaterials composed of metallic antennae arrays are used as they possess extraordinary optical transmission(EOT)in the terahertz(THz)region,whereby a giant forward light propagation can be created using constructive interference of tunneling surface plasmonic waves.However,numerous applications of THz meta-devices demand an active manipula-tion of the THz beam in free space.Although some studies have been carried out to control the EOT for the THz region,few of these are based upon electrical modulation of the EOT phenomenon,and novel strategies are required for act-ively and dynamically reconfigurable EOT meta-devices.In this work,we experimentally present that the EOT resonance can be coupled to optically reconfigurable chalcogenide metamaterials which offers a reversible all-optical control of the THz light.A modulation efficiency of 88%in transmission at 0.85 THz is experimentally observed using the EOT metama-terials,which is composed of a gold(Au)circular aperture array sitting on a non-volatile chalcogenide phase change ma-terial(Ge2Sb2Te5)film.This comes up with a robust and ultrafast reconfigurable EOT over 20 times of switching,excited by a nanosecond pulsed laser.The measured data have a good agreement with finite-element-method numerical simula-tion.This work promises THz modulators with significant on/off ratios and fast speeds.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10525419,60736041 and 10874238)the National Key Basic Research Special Foundation of China (Grant No. 2006CB302901)
文摘We fabricate a series of periodic arrays of subwavelength square and rectangular air holes on gold films, and measure the transmission spectra of these metallic nanostructures. By changing some geometrical and physical parameters, such as array period, air hole size and shape, and the incident light polarization, we verify that both global surface plasmon resonance and localized waveguide mode resonance are influential on enhancing the transmission of light through nanostructured metal films. These two resonances induce different behaviours of transmission peak shift. The transmission through the rectangular air-hole structures exhibits an obvious polarization effect dependent on the morphology. Numerical simulations are also made by a plane-wave transfer-matrix method and in good consistency with the experimental results.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11074145,10874124,and 61275028)
文摘In this paper we study the extraordinary optical transmission of one-dimensional multi-slits in an ideal metal film.The transmissivity is calculated as a function of various structural parameters.The transmissivity oscillates,with the period being just the light wavelength,as a function of the spacing between slits.As the number of slits increases,the transmissivity varies in one of three ways.It can increase,attenuate,or remain basically unchanged,depending on the spacing between slits.Each way is in an oscillatory manner.The slit interaction responsible for the oscillating transmission strength that depends on slit spacing is the subject of more detailed investigation.The interaction most intuitively manifests as a current distribution in the metal surface between slits.We find that this current is attenuated in an oscillating fashion from the slit corners to the center of the region between two adjacent slits,and we present a mathematical expression for its waveform.
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB921503,2013CB632904 and 2013CB632702the National Natural Science Foundation of China under Grant No 1134006+2 种基金the Natural Science Foundation of Jiangsu Province under Grant No BK20140019the Project Funded by the Priority Academic Program Development of Jiangsu Higher Educationthe China Postdoctoral Science Foundation under Grant Nos 2012M511249 and 2013T60521
文摘We investigate both experimentally and numerically a complex structure, where ＇face-to-face＇ Helmholtz resonance cavities （HRCs） are introduced to construct a one-dimensional acoustic grating. In this system, pairs of HRCs can intensely couple with each other in two forms： a bonding state and an anti-bonding state, analogous to the character of hydrogen molecule with two atoms due to the interference of wave functions of sound among the acoustic local-resonating structures. The bonding state is a ＇bright＇ state that interferes with the Fabry-Pbrot resonance mode, thereby causing this state to break up into two modes as the splitting of the extraordinary acoustic transmission peak. On the contrary, the anti-bonding state is a ＇dark＇ state in which the resonance mode remains entirely localized within the HRCs, and has no contribution to the acoustic transmission.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB921504)the National Natural Science Foundation of China(GrantNos.11104139,11274171,11274099,and 11204145)+1 种基金SRFDP(Grant Nos.20110091120040,20120091110001,and 20130091130004)the NaturalScience Foundation of Jiangsu Province,China(Grant No.BK2011542)
文摘Extraordinary acoustic transmission （EAT） has been investigated in a tunable bull＇s eye structure. We demonstrate that the transmission coefficient of acoustic waves can be modulated by a grating structure. When the grating is located at a distance of 0.5 mm from the base plate, the acoustic transmission shows an 8.77-fold enhancement compared to that by using a traditional bull＇s eye structure. When the distance increases to 1.5 mm, the transmission approaches zero, indicating a total reflection. Thus, we can make an efficient modulation of acoustic transmission from 0 to 877%. The EAT effects have been ascribed to the coupling of structure-induced resonance with the diffractive wave and the waveguide modes, as well as the Fabry-Perot resonances. As a potential application, the modulation of far-field collimation is illustrated in the proposed bull＇s eye structure.
基金Project supported by the National Basic Research Program of China （Grant Nos. 2011CBA00110 and 2011CBA00107） and the National Natural Science Foundation of China.
文摘We studied numerically the temperature dependent extraordinary terahertz transmission through niobium nitride(NbN) film perforated with subwavelength spindle-like apertures. Both the resonant frequency and intensity of extraordinary terahertz transmission peaks can be greatly modified by the transition of NbN film from the normal state to the superconducting state. An enhancement of the(±1, 0) NbN/magnesium oxide(MgO) peak intensity as high as 200% is demonstrated due to the combined contribution of both the superconducting transition and the excitation of localized surface plasmons(LSPs) around the apertures. The extraordinary terahertz transmission through spindle-like hole arrays patterned on the NbN film can pave the way for us to explore novel active tuning devices.
基金supported by the National Natural Science Foundation of China (Grant No 10704079)
文摘Metallic gratings with narrow slits can lead to special optical properties such as strongly enhancing the trans- mission and considerably strengthening the polarized effect. A narrow-band filter suitable for application in optical communication is designed by sandwiching a metallic grating between two identical dielectric films. The maximum transmission can reach 96% after optimizing the parameters of films and grating at a central wavelength of 1053 nm. It is the first time, to our knowledge, that such high transmission has been reported since the discovery of the extraordinarily high transmission through periodic holes or slits; moreover, the extremely polarized effect is also found in P mode of this symmetric grating.
文摘We experimentally detect high-refractive-index media (n > 1.5) using a surface plasmon resonance (SPR) sensor with a diffraction grating. While SPR sensors are generally based on the attenuated total reflection method using metal films, here, we focus on a method using a diffraction grating, which can detect relatively higher refractive-index media and is suitable for device miniaturization. In this study, we used the rigorous coupled-wave analysis method to simulate the dependence of the reflectance on an incident angle for media with refractive index values up to 1.700. In the experiment, a medium (n = 1.660 - 1.700) was successfully detected using this grating. Under the conditions of the grating (period: 600 nm, Au thickness: 40 nm) using a red laser (λ: 635 nm), a sharp decline in the reflectance and a rise in the transmittance at certain angles were confirmed, demonstrating the extraordinary transmission enabled by SPR. Because excitation angles changed with changes in the refractive index, we concluded that this method can be applied to sensors that detect high-refractive-index media.
基金National Natural Science Foundation of China(NSFC)(11604217,11574218,11734012,61420106014,61522504)Fundamental Research Funds for the Central Universities(21617410)Guangdong Provincial Innovation and Entrepreneurship Project(2016ZT06D081)
文摘We show that a metasurface composed of a subwavelength metallic slit array embedded in an asymmetric dielectric environment can exhibit either diffraction （EOD）. The cascaded refractive extraordinary optical transmission （EOT） or extraordinary optical indices of the dielectrics can leverage multiple decaying passages into variant subsections with different diffraction order combinations according to the diffraction order chart in the k-vector space, providing a flexible by changing the wavevector of the efficiencies can be enhanced to near or EOD in a single tional metasurface onstrated. Our findings incident light. As a result, either the unity by the excitation of the localized provide a convenient way components on a single planar device.
文摘Electrochemical （EC） reactions play vital roles in many disciplines, and its molecular-level understanding is highly desired, in particular under reactions. The vibration spectroscopy is a powerful in situ technique for chemical analysis, yet its application to EC reactions is hindered by the strong attenuation of infrared （IR） light in both electrodes and electrolytes. Here we demonstrate that by incorporating appropriate sub-wavelength plasmonic structures at the metal electrode, the IR field at the EC interface can be greatly enhanced via the excitation of surface plasmon. This scheme facilitates in situ vibrational spectroscopic studies, especially using the surface-specific sum-frequency generation technique.
基金Project supported by the National Key Basic Research Program of China(973 Program)(Grant Nos.2011CB933102,2010CB934104,and 2011CB933203)the National Natural Science Foundation of China(Grant Nos.61036009 and 61378058)the Science Innovation Foundation of the Cooperation Project between Jilin Province and Chinese Academy of Sciences(Grant No.2012CJT0037)
文摘The extraordinary optical transmission （EOT） phenomenon of nano-periodic aperture array in metallic film has been widely investigated and used in biosensors. The surface plasmon resonance and cavity mode in some periodic nanos- tructures, such as nanohole and nanoslit, cause EOTs at certain wavelengths. This resonance wavelength is sensitive to the refractive index on the surface of periodic nanostructures. Therefore, the metallic nanostructures are expected to be good sensing elements. The sensing performances of gold nanoslit arrays are experimentally and theoretically investigated. Three-dimensional finite difference time domain （FDTD） simulations are utilized to explore their transmission spectra and steady-state field intensity distributions. The electron beam evaporation, electron beam lithography, and ion milling are applied to the gold nanoslit arrays with different widths and periods. The sensing performances of the gold nanoslit ar- ray are characterized via transmission spectra in four kinds of refractive index samples. The highest sensitivity reaches 726 nm/RIU when the width of the gold nanoslit array is 38.5 nm.
文摘We studied the infrared transmission properties of gold films on ordered two-dimensional nonclose- packed polystyrene （PS） colloidal crystal. The gold films consist of gold half-shells on the PS spheres and gold film with 2D arrays of holes on the glass substrate. An extraordinary optical transmission phenomenon could be found in such a structure. Simulations with the finite-difference time-domain method were also employed to get the transmission spectra and electric field distribution. The transmission response of the samples can be adjusted by controlling the thickness of the gold films. Angle-resolved measurements were performed using polarized light to obtain more information about the surface plasmon polariton resonances of the gold films. As the angle changes, the transmission spectra change a lot. The transmission spectra of p-polarized light have quite different properties compared to those of s-polarized light.
基金financial support from the National Key R&D Program of China(Nos.2023YFB3811400,2022YFB3806000)the National Natural Science Foundation of China(Nos.12074314,52202370,52332006)+2 种基金the Aeronautical Science Foundation of China(No.20230018053007)the Science and Technology New Star Program of Shaanxi Province(No.2023KJXX-148)the Fundamental Research Funds for the Central Universities,and China Postdoctoral Science Foundation(No.2023T160359).
文摘Reconfigurable metamaterials significantly expand the application scenarios and operating frequency range of metamaterials,making them promising candidates for use in smart tunable device.Here,we propose and experimentally demonstrate that integrating metamaterial design principles with the intrinsic features of natural materials can engineer thermal smart metadevices.Tunable extraordinary optical transmission like(EOT-like)phenomena have been achieved in the microwave regime using shape memory alloy(SMA).The strongly localized fields generated by designed metadevices,combined with the intense interference of incident waves,enhance transmission through subwavelength apertures.Leveraging the temperature-responsive properties of SMA,the morphology of the metadevice can be recontructed,thereby modifying its response to electromagnetic waves.The experiments demonstrated control over the operating frequency and transmission amplitude of EOT-like behavior,achieving a maximum transmission enhancement factor of 126.Furthermore,the metadevices with modular design enable the realization of multiple functions with independent control have been demonstrated.The proposed SMA-based metamaterials offer advantages in terms of miniaturization,easy processing,and high design flexibility.They may have potential applications in microwave devices requiring temperature control,such as sensing and monitoring.
基金supported by the National Natural Science Foundation of China(Grant Nos.62375036,62005034,62171076,and 61727816)Liaoning Cancer Hospital&Institute“Oncology+”Funds(Grant No.2024-ZLKF-34)Fundamental Research Funds for the Central Universities(Grant No.DUT21RC(3)080).
文摘Since the discovery of the extraordinary optical transmission phenomenon,nanohole arrays have attracted much attention and been widely applied in sensing.However,their typical fabrication process,utilizing photolithographic top-down manufacturing technologies,has intrinsic drawbacks including the high costs,time consumption,small footprint,and low throughput.This study presented a low-cost,high-throughput,and scalable method for fabricating centimeter-scale(1×2 cm2)nanohole arrays using the improved nanosphere lithography.The large-scale close-packed polystyrene monolayers obtained by the hemispherical-depression-assisted self-assembly method were employed as colloidal masks for the nanosphere lithography,and the nanohole diameter was tuned from 233 nm to 346 nm with a fixed period of 420 nm via plasma etching.The optical properties and sensing performance of the nanohole arrays were investigated,and two transmission dips were observed due to the resonant coupling of plasmonic modes.Both dips were found to be sensitive to the surrounding environment,and the maximum bulk refractive index sensitivity was up to 162.1 nm/RIU with a 233 nm hole diameter.This study offered a promising approach for fabricating large-scale highly ordered nanohole arrays with various periods and nanohole diameters that could be used for the development of low-cost and high-throughput on-chip plasmonic sensors.
