Metamaterials(MMs)have become increasingly prominent in terahertz flexible devices.However,bending deformation often alters the structure of the unit,which affects the response performance and stability of MMs.Here,a ...Metamaterials(MMs)have become increasingly prominent in terahertz flexible devices.However,bending deformation often alters the structure of the unit,which affects the response performance and stability of MMs.Here,a metal-aperture metamaterial(MA-MM)utilizing the strong coupling effect induced by two resonance modes is innovatively proposed to address the mentioned limitations.Specifically,it is found that the coupling state between multiple resonance modes remains consistent at different bending angles.Under these circumstances,the generated Rabi splitting peak presents stable response performance even under low resonance intensity caused by excessive deformation.The experimental results demonstrate that despite the amplitude of two resonant peaks decreasing significantly by 87.6%,the Q-factor of the Rabi splitting only reduced by 14.8%.Furthermore,armed with the response mode of the Rabi splitting being unaffected by plasma excitation range,the designed MA-MMs are able to maintain constant Q-factors and frequencies on curved surfaces of varying sizes.These findings exhibit the characteristics of electromagnetic response for multi-mode resonance-coupled MAMMs on different curved surfaces,presenting a novel design approach for terahertz flexible functional devices.展开更多
As a nondestructive testing technique,terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings(TBCs).However,the invisibility of ceramic/therm...As a nondestructive testing technique,terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings(TBCs).However,the invisibility of ceramic/thermally grown oxide(TGO)reflective wave leads to the measurement failure of natural growth TGO whose thickness is below 10μm in TBCs.To detect and monitor TGO in the emergence stage,a time of flight(TOF)improved TGO thickness measurement method is proposed.A simulative investigation on propagation characteristics of terahertz shows the linear relationship between TGO thickness and phase shift of feature wave.The accurate TOF increment could be acquired from wavelet soft threshold and cross-correlation function with negative effect reduction of environmental noise and system oscillation.Thus,the TGO thickness could be obtained efficiently from the TOF increment of the monitor area with different heating times.The averaged error of 1.61μm in experimental results demonstrates the highly accurate and robust measurement of the proposed method,making it attractive for condition monitoring and life prediction of TBCs.展开更多
基金National Natural Science Foundation of China(52275096,72304127)Fujian Provincial Major Research Project(2022HZ024005)+1 种基金Science and Technology Planning Project of Fuzhou(2022-P-022)Natural Science Foundation of Fujian Province(2022J01071).
文摘Metamaterials(MMs)have become increasingly prominent in terahertz flexible devices.However,bending deformation often alters the structure of the unit,which affects the response performance and stability of MMs.Here,a metal-aperture metamaterial(MA-MM)utilizing the strong coupling effect induced by two resonance modes is innovatively proposed to address the mentioned limitations.Specifically,it is found that the coupling state between multiple resonance modes remains consistent at different bending angles.Under these circumstances,the generated Rabi splitting peak presents stable response performance even under low resonance intensity caused by excessive deformation.The experimental results demonstrate that despite the amplitude of two resonant peaks decreasing significantly by 87.6%,the Q-factor of the Rabi splitting only reduced by 14.8%.Furthermore,armed with the response mode of the Rabi splitting being unaffected by plasma excitation range,the designed MA-MMs are able to maintain constant Q-factors and frequencies on curved surfaces of varying sizes.These findings exhibit the characteristics of electromagnetic response for multi-mode resonance-coupled MAMMs on different curved surfaces,presenting a novel design approach for terahertz flexible functional devices.
基金the National Natural Science Foundation of China(Grant Nos.52275096,51905102)the Fujian Provincial Science and Technology Project,China(Grant No.2019I0004)+2 种基金the State Key Laboratory of Mechanical Systems and Vibration,China(Grant No.MSV-2018-07)the Shanghai Natural Sciences Fund,China(Grant No.18ZR1414200)the China Postdoctoral Science Foundation(Grant No.2019M662226).
文摘As a nondestructive testing technique,terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings(TBCs).However,the invisibility of ceramic/thermally grown oxide(TGO)reflective wave leads to the measurement failure of natural growth TGO whose thickness is below 10μm in TBCs.To detect and monitor TGO in the emergence stage,a time of flight(TOF)improved TGO thickness measurement method is proposed.A simulative investigation on propagation characteristics of terahertz shows the linear relationship between TGO thickness and phase shift of feature wave.The accurate TOF increment could be acquired from wavelet soft threshold and cross-correlation function with negative effect reduction of environmental noise and system oscillation.Thus,the TGO thickness could be obtained efficiently from the TOF increment of the monitor area with different heating times.The averaged error of 1.61μm in experimental results demonstrates the highly accurate and robust measurement of the proposed method,making it attractive for condition monitoring and life prediction of TBCs.
