The simulation mechanism of surface plasmon polaritons(SPPs)and localized surface plasmon(LSP)in different structures was studied,including the Au reflection grating(Au grating),Au substrate with dielectric ribbons gr...The simulation mechanism of surface plasmon polaritons(SPPs)and localized surface plasmon(LSP)in different structures was studied,including the Au reflection grating(Au grating),Au substrate with dielectric ribbons grating(Au substrate grating),and pure electric conductor(PEC)substrate with Au ribbons grating(Au ribbons grating).And the characteristics of the Smith-Purcell radiation in these structures were presented.Simulation results show that SPPs are excited on the bottom surface of Au substrate grating grooves and LSP is stimulated on the upper surface both of Au ribbons grating grooves and Au grating grooves.Owing to the irreconcilable contradiction between optimizing the grating diffraction radiation efficiency and optimizing the SPPs excitation efficiency in the Au substrate grating,only 40-times enhancement of the radiation intensity was obtained by excited SPPs.However,the LSP enhanced structure overcomes the above problem and gains much better radiation enhancement ability,with about 200-times enhancement obtained in the Au ribbons grating and more than 500-times enhancement obtained in the Au grating.The results presented here provide a way of developing miniature,integratable,tunable,high-power-density radiation sources from visible light to ultraviolet rays at room temperature.展开更多
A unidirectional surface plasmon polaritons(SPPs) generator with greatly enhanced generation efficiency is proposed. The SPPs generator consists of an asymmetric single nanoslit coated with a polyviny alcohol(PVA) fil...A unidirectional surface plasmon polaritons(SPPs) generator with greatly enhanced generation efficiency is proposed. The SPPs generator consists of an asymmetric single nanoslit coated with a polyviny alcohol(PVA) film and a silver rectangle block. The generation efficiency of this SPPs generator is investigated using the finite difference time domain method. Due to the presence of the silver rectangle block, the SPPs generation efficiency of the asymmetric single nanoslit with PVA film can be greatly enhanced and the corresponding wavelength with the maximum enhancement factor can be tuned flexibly. The influence of the structural parameters on the generation efficiency is also investigated for the enhanced unidirectional SPPs generator.展开更多
This paper describes a multi-reflected mode based on a narrow waveguide to enlarge the interferential area of surface plasmon polaritons (SPPs). A reasonable thickness of metal film is coated under the waveguide, th...This paper describes a multi-reflected mode based on a narrow waveguide to enlarge the interferential area of surface plasmon polaritons (SPPs). A reasonable thickness of metal film is coated under the waveguide, the incident angle and the waveguide thickness are optimized in order to effectively increase interferential area. This is a key point for research into the Coos Hǎnchen shift to optimize the waveguide thickness. Finally, the SPP interferential field is simulated with the finite-difference time-domain (FDTD) technique to prove the optimized results, and indicates that not only is the interferential area enlarged, but the high contrast is also maintained. Furthermore, the mode can fabricate some specific interferential patterns by adding some modulating techniques to the waveguide. So the mode has potential application in the fabrication of sub-wavelength patterns.展开更多
Surface plasmon polaritons'(SPPs')frequency blue shift is observed in finite-difference time-domain(FDTD)simulation of parallel electron excitation Au bulk structure.Comparing with cold dispersion of SPPs,an o...Surface plasmon polaritons'(SPPs')frequency blue shift is observed in finite-difference time-domain(FDTD)simulation of parallel electron excitation Au bulk structure.Comparing with cold dispersion of SPPs,an obvious frequency blue shift is obtained in low confinement region excitation simulation results.Then,according to SPPs'transverse attenuation characteristics,the excited frequency mode instead of cold dispersion corresponding frequency mode matches it.Thence,this excited mode is confirmed to be SPPs'mode.As is well known the lower the frequency,the smaller the confinement factor is and the lower the excitation efficiency,the wider the bandwidth of excited SPPs is.And considering the attenuation in whole structure,the excited surface field contains attenuation signal.In a low confinement factor region,the higher the SPPs'frequency,the higher the excitation efficiency is,while broadband frequency information obtained in attenuation signal provides high frequency information in stimulation signal.Thence,in the beam-wave interaction,as the signal oscillation time increases,the frequency of the oscillation field gradually increases.Thus,compared with cold dispersion,the frequency of excited SPP is blueshifted This hypothesis is verified by monitoring the time domain signal of excited field in low and high confinement factor regions and comparing them.Then,this frequency-blue shift is confirmed to have commonality of SPPs,which is independent of SPPs'material and structure.Finally,this frequency-blue shift is confirmed in an attenuated total reflection(ATR)experiment.Owing to frequency dependence of most of SPPs'devices,such as coherent enhancement radiation and enhancement transmission devices,the frequency-blue shift presented here is of great influence in the SPPs applications.展开更多
A single metallic nanoslit is employed for investigating the contribution of Surface Plasmon Polaritons(SPPs) to Extraordinary Optical Transmission(EOT) based on rigorous electromagnetic theory and the Spectrum Analys...A single metallic nanoslit is employed for investigating the contribution of Surface Plasmon Polaritons(SPPs) to Extraordinary Optical Transmission(EOT) based on rigorous electromagnetic theory and the Spectrum Analysis Method(SAM). Numerical results shows that the SPP is the main factor responsible for the EOT, and a phase singularity is observed.展开更多
The use of an attenuated total reflection-coupling mode of prism coated with metal film to excite the interference of the surface plasmon polaritons (SPPs) was proposed for periodic patterning with a resolution of s...The use of an attenuated total reflection-coupling mode of prism coated with metal film to excite the interference of the surface plasmon polaritons (SPPs) was proposed for periodic patterning with a resolution of subwavelength scale. High intensity of electric field can be obtained because of the coupling between SPPs and evanescence under a resonance condition, which can reduce exposure time and improve contrast. In this paper, several critical parameters for maskless surface plasmon resonant lithography are described, and the preliminary simulation based on a finite difference timedomain technique agrees well with the theoretical analysis, which demonstrates this scheme and provides the theoretical basis for further experiments.展开更多
We propose to use wavelength modulation approach,i.e.,the spectroscopy of a surface plasmon in the frequency domain,to characterize the optical dispersion property of gold film.Using this method,we determine the dispe...We propose to use wavelength modulation approach,i.e.,the spectroscopy of a surface plasmon in the frequency domain,to characterize the optical dispersion property of gold film.Using this method,we determine the dispersion relationship of gold film in a wavelength range from 537.12 nm to 905.52 nm,and our results accord well with the reported results by other authors.This method is particularly suited for studying the optical dispersion properties of thin metal films,because a series of dielectric constants over a wide spectral range can be determined simultaneously via only a single scan of the incident angle,thereby avoiding the repeated measurements required when using the angular modulation approach.展开更多
A hybrid structure based on a planar waveguide (PWG) mode coupling a long-range surface plasmon resonance (LRSPR) mode is proposed to enhance the GH shift. Both the PWG mode and LRSPR mode can be in strong resonan...A hybrid structure based on a planar waveguide (PWG) mode coupling a long-range surface plasmon resonance (LRSPR) mode is proposed to enhance the GH shift. Both the PWG mode and LRSPR mode can be in strong resonance, and these two modes can be coupled together due to the normal-mode splitting. The largest GH shift of PWG-coupled LRSPR structure is 4156 times that of the incident beam, which is 23 times and 3.6 times that of the surface plasmon resonance (SPR) structure and the LRSPR structure, respectively. As a GH shift sensor, the highest sensitivity of 4.68 x 107 λ is realized in the coupled structure. Compared with the sensitivity of the traditional SPR structure, the sensitivity of our structure is increased by more than 2 orders, which theoretically indicates that the proposed configuration can be applied to the field of high-sensitivity sensors in the future.展开更多
Knowledge of surface plasmon polariton (SPP) modes in one-dimensional (1D) metallic nanostructures is essential for the development of subwavelength optical devices such as photonic circuits, integrated light sour...Knowledge of surface plasmon polariton (SPP) modes in one-dimensional (1D) metallic nanostructures is essential for the development of subwavelength optical devices such as photonic circuits, integrated light sources, and photo- detectors. Despite many efforts to characterize the propagation parameters of these subwavelength 1D plasmonic waveguides, such as Ag nanowires, large discrepancies exist among available reports owing to their sensitivity to the relative weights of co-existing SPP modes and the lack of a method of decoupling these modes and analyzing them separately. In this work, we develop an interference method to distinguish different SPP modes that are simultaneously excited in a Ag nanowire waveguide and measure their propagation parameters separately. By extracting information from the propagation-distance- dependent intensity oscillations of the scattered light from the nanowire tip, the effective refractive indices, propagation lengths, and relative mode weights of co-existing SPP modes supported by the nanowire are derived from a mode interference model. These parameters depend strongly on the nanowire diameter and excitation wavelength. In particular, we demonstrate the possibility of selective excitation of different SPP modes by varying the nanowire diameter. This new mode analysis technique provides unique insights into the develop- ment and optimization of SPP-based applications.展开更多
As a basic optical device, the optical directional coupler (ODC) is basically used as optical splitters, optic switches and so on. A novel ODC employing surface plas- mon polaritons (SPPs) is proposed for high integra...As a basic optical device, the optical directional coupler (ODC) is basically used as optical splitters, optic switches and so on. A novel ODC employing surface plas- mon polaritons (SPPs) is proposed for high integration. The finite difference time domain (FDTD) method is adopted to simulate and analyze its properties. Results show that the ODC proposed here follows the general regulations of a conventional dielectric ODC, but its transverse size is of nanoscale, which improves the optical integration greatly. For 1550 nm and 1310 nm input wavelengths, when the coupling region length (L) equals half of its coupling length, the Excess Loss is respectively 0.57 dB and 0.56 dB, which is practical in applications. So the research on the present ODC is of some practical importance.展开更多
Surface plasmon polariton (SPP) is an attractive candidate to improve internal quantum efficiency (QE) of spontaneous emission (SE) from nano-structured silicon (Si) including nano-porous silicon (NP-Si) and...Surface plasmon polariton (SPP) is an attractive candidate to improve internal quantum efficiency (QE) of spontaneous emission (SE) from nano-structured silicon (Si) including nano-porous silicon (NP-Si) and silicon nanocrystal (Si-NC). Since the SPP resonant frequency of common metals, e.g., gold (Au), silver (Ag), copper (Cu), and aluminum (A1), is too high, the SPP resonance has to be engineered to match the luminescence from nano- structured Si. For this purpose, we have proposed and demonstrated three approaches including metal-rich Au(1-a)-SiO2(a) cermet SPP waveguide (WG), com- pound layer structure WG and metallic grating. In this paper, those approaches are reviewed and discussed. According to the calculated results, such three methods could effectively enhance SE rate from NP-Si or Si-NCs and show potential in developing high efficiency Si based light sources with electric pump.展开更多
In this paper,we propose a photonic crystal fiber(PCF)polarization filter based on surface plasmon resonance(SPR)characteristics.Gold nanowire is used as the active plasmonic material.Light into silica core becomes co...In this paper,we propose a photonic crystal fiber(PCF)polarization filter based on surface plasmon resonance(SPR)characteristics.Gold nanowire is used as the active plasmonic material.Light into silica core becomes coupled to gold nanowire stimulating SPR. It soplits light into two orthogonal(x-polarization and y-polarization)polarization in the second order of surface plasmon polarization.Numerical investigations of the proposed PCF filter is finite element method(FEM).By position,the performance of the propsed PCF filter is inspected rigorously.Filtering of any polarization can be obtained by properly placing the metal wires.The maximum cnfinement loss of x-polarization is 692.25dB/cm and y-polarization is 1.13dB/cm offers at resonance position 1.42μm.Such a confinement loss difference between two orthogonal polarizations makes PCF a talented candidate to filter devicees.Consequently,the recommended PCF structure is useful for polarization device.展开更多
基金supported by the National Key Research and Development Program of China under Grants No.2017YFA0701000,No.2018YFF01013001,and No.2020YFA0714001the Natural Science Foundation of China under Grants No.61988102,No.61921002,and No.62071108。
文摘The simulation mechanism of surface plasmon polaritons(SPPs)and localized surface plasmon(LSP)in different structures was studied,including the Au reflection grating(Au grating),Au substrate with dielectric ribbons grating(Au substrate grating),and pure electric conductor(PEC)substrate with Au ribbons grating(Au ribbons grating).And the characteristics of the Smith-Purcell radiation in these structures were presented.Simulation results show that SPPs are excited on the bottom surface of Au substrate grating grooves and LSP is stimulated on the upper surface both of Au ribbons grating grooves and Au grating grooves.Owing to the irreconcilable contradiction between optimizing the grating diffraction radiation efficiency and optimizing the SPPs excitation efficiency in the Au substrate grating,only 40-times enhancement of the radiation intensity was obtained by excited SPPs.However,the LSP enhanced structure overcomes the above problem and gains much better radiation enhancement ability,with about 200-times enhancement obtained in the Au ribbons grating and more than 500-times enhancement obtained in the Au grating.The results presented here provide a way of developing miniature,integratable,tunable,high-power-density radiation sources from visible light to ultraviolet rays at room temperature.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11174237 and 10974161), the National Basic Research Program of China (Grant No. 2013CB328904), the Fundamental Research Funds for the Central Universities of Ministry of Education of China (Grant Nos. SWJTU 12CX084 and SWJTU2(/10ZT06), and the Innovation Fund for Ph.D. Student of Southwest Jiaotong University, China.
文摘A unidirectional surface plasmon polaritons(SPPs) generator with greatly enhanced generation efficiency is proposed. The SPPs generator consists of an asymmetric single nanoslit coated with a polyviny alcohol(PVA) film and a silver rectangle block. The generation efficiency of this SPPs generator is investigated using the finite difference time domain method. Due to the presence of the silver rectangle block, the SPPs generation efficiency of the asymmetric single nanoslit with PVA film can be greatly enhanced and the corresponding wavelength with the maximum enhancement factor can be tuned flexibly. The influence of the structural parameters on the generation efficiency is also investigated for the enhanced unidirectional SPPs generator.
基金Project supported by the National Basic Research of China (Grant No 2006CD302902)the National Natural Science Foundation of China (Grant Nos 60676024 and 60878031)the Specialized Research Fund of China for the Doctoral Program of Higher Education (Grant No 20060610006)
文摘This paper describes a multi-reflected mode based on a narrow waveguide to enlarge the interferential area of surface plasmon polaritons (SPPs). A reasonable thickness of metal film is coated under the waveguide, the incident angle and the waveguide thickness are optimized in order to effectively increase interferential area. This is a key point for research into the Coos Hǎnchen shift to optimize the waveguide thickness. Finally, the SPP interferential field is simulated with the finite-difference time-domain (FDTD) technique to prove the optimized results, and indicates that not only is the interferential area enlarged, but the high contrast is also maintained. Furthermore, the mode can fabricate some specific interferential patterns by adding some modulating techniques to the waveguide. So the mode has potential application in the fabrication of sub-wavelength patterns.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0701000,2018YFF01013001,and 2020YFA0714001)the National Natural Science Foundation of China(Grant Nos.61988102,61921002,and 62071108).
文摘Surface plasmon polaritons'(SPPs')frequency blue shift is observed in finite-difference time-domain(FDTD)simulation of parallel electron excitation Au bulk structure.Comparing with cold dispersion of SPPs,an obvious frequency blue shift is obtained in low confinement region excitation simulation results.Then,according to SPPs'transverse attenuation characteristics,the excited frequency mode instead of cold dispersion corresponding frequency mode matches it.Thence,this excited mode is confirmed to be SPPs'mode.As is well known the lower the frequency,the smaller the confinement factor is and the lower the excitation efficiency,the wider the bandwidth of excited SPPs is.And considering the attenuation in whole structure,the excited surface field contains attenuation signal.In a low confinement factor region,the higher the SPPs'frequency,the higher the excitation efficiency is,while broadband frequency information obtained in attenuation signal provides high frequency information in stimulation signal.Thence,in the beam-wave interaction,as the signal oscillation time increases,the frequency of the oscillation field gradually increases.Thus,compared with cold dispersion,the frequency of excited SPP is blueshifted This hypothesis is verified by monitoring the time domain signal of excited field in low and high confinement factor regions and comparing them.Then,this frequency-blue shift is confirmed to have commonality of SPPs,which is independent of SPPs'material and structure.Finally,this frequency-blue shift is confirmed in an attenuated total reflection(ATR)experiment.Owing to frequency dependence of most of SPPs'devices,such as coherent enhancement radiation and enhancement transmission devices,the frequency-blue shift presented here is of great influence in the SPPs applications.
基金supported by the National Basic Research Program of China(Grant No.2006CB302901)the InnovationTeam Development Program of the Chinese Ministry of Education(Grant No.IRT0606)
文摘A single metallic nanoslit is employed for investigating the contribution of Surface Plasmon Polaritons(SPPs) to Extraordinary Optical Transmission(EOT) based on rigorous electromagnetic theory and the Spectrum Analysis Method(SAM). Numerical results shows that the SPP is the main factor responsible for the EOT, and a phase singularity is observed.
基金supported by the National Basic Research of China (Grant No 2006CD302900-2)the National Natural Science Foundation of China (Grant No 60676024)the Specialized Research Fund of China for the Doctoral Program of Higher Education (Grant No 20060610006)
文摘The use of an attenuated total reflection-coupling mode of prism coated with metal film to excite the interference of the surface plasmon polaritons (SPPs) was proposed for periodic patterning with a resolution of subwavelength scale. High intensity of electric field can be obtained because of the coupling between SPPs and evanescence under a resonance condition, which can reduce exposure time and improve contrast. In this paper, several critical parameters for maskless surface plasmon resonant lithography are described, and the preliminary simulation based on a finite difference timedomain technique agrees well with the theoretical analysis, which demonstrates this scheme and provides the theoretical basis for further experiments.
基金Project supported by the National Natural Science Foundation of China (Grant No. 61177079)the Open Fund of Key Laboratory of Electronics Engineering,College of Heilongjiang Province,China (Grant No. DZZD20100014)the Youth Science Foundation of Heilongjiang University,China (Grant No. QL200914)
文摘We propose to use wavelength modulation approach,i.e.,the spectroscopy of a surface plasmon in the frequency domain,to characterize the optical dispersion property of gold film.Using this method,we determine the dispersion relationship of gold film in a wavelength range from 537.12 nm to 905.52 nm,and our results accord well with the reported results by other authors.This method is particularly suited for studying the optical dispersion properties of thin metal films,because a series of dielectric constants over a wide spectral range can be determined simultaneously via only a single scan of the incident angle,thereby avoiding the repeated measurements required when using the angular modulation approach.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61505111 and 11604216)the China Postdoctoral Science Foundation(Grant No.2016M600667)+2 种基金the Science and Technology Planning Project of Guangdong Province,China(Grant No.2016B050501005)the Fund from the Educational Commission of Guangdong Province,China(Grant No.2016KCXTD006)the Natural Science Foundation of Guangdong Province,China(Grant No.2015A030313549)
文摘A hybrid structure based on a planar waveguide (PWG) mode coupling a long-range surface plasmon resonance (LRSPR) mode is proposed to enhance the GH shift. Both the PWG mode and LRSPR mode can be in strong resonance, and these two modes can be coupled together due to the normal-mode splitting. The largest GH shift of PWG-coupled LRSPR structure is 4156 times that of the incident beam, which is 23 times and 3.6 times that of the surface plasmon resonance (SPR) structure and the LRSPR structure, respectively. As a GH shift sensor, the highest sensitivity of 4.68 x 107 λ is realized in the coupled structure. Compared with the sensitivity of the traditional SPR structure, the sensitivity of our structure is increased by more than 2 orders, which theoretically indicates that the proposed configuration can be applied to the field of high-sensitivity sensors in the future.
文摘Knowledge of surface plasmon polariton (SPP) modes in one-dimensional (1D) metallic nanostructures is essential for the development of subwavelength optical devices such as photonic circuits, integrated light sources, and photo- detectors. Despite many efforts to characterize the propagation parameters of these subwavelength 1D plasmonic waveguides, such as Ag nanowires, large discrepancies exist among available reports owing to their sensitivity to the relative weights of co-existing SPP modes and the lack of a method of decoupling these modes and analyzing them separately. In this work, we develop an interference method to distinguish different SPP modes that are simultaneously excited in a Ag nanowire waveguide and measure their propagation parameters separately. By extracting information from the propagation-distance- dependent intensity oscillations of the scattered light from the nanowire tip, the effective refractive indices, propagation lengths, and relative mode weights of co-existing SPP modes supported by the nanowire are derived from a mode interference model. These parameters depend strongly on the nanowire diameter and excitation wavelength. In particular, we demonstrate the possibility of selective excitation of different SPP modes by varying the nanowire diameter. This new mode analysis technique provides unique insights into the develop- ment and optimization of SPP-based applications.
基金the Project of Guangdong Natural Science Funds for the Research on Nano-integrated Waveguide Devices Based On Surface Plasmon Polariton (Grant No. 07117866)the Key Project of the Natural Science Foundation of Guangdong Province of China (Grant No. 05200534)
文摘As a basic optical device, the optical directional coupler (ODC) is basically used as optical splitters, optic switches and so on. A novel ODC employing surface plas- mon polaritons (SPPs) is proposed for high integration. The finite difference time domain (FDTD) method is adopted to simulate and analyze its properties. Results show that the ODC proposed here follows the general regulations of a conventional dielectric ODC, but its transverse size is of nanoscale, which improves the optical integration greatly. For 1550 nm and 1310 nm input wavelengths, when the coupling region length (L) equals half of its coupling length, the Excess Loss is respectively 0.57 dB and 0.56 dB, which is practical in applications. So the research on the present ODC is of some practical importance.
基金Acknowledgements This work was supported by the National Basic Research Program of China (No. 2011CBA00600 and 2007CB307004) and the National Natural Science Foundation of China (Grant Nos. 60877023, 61036010, 61036011, and 61107050). The authors would like to thank Xuan Tang, Weiwei Ke, Wei Zhang and Jiangde Peng for their valuable discussions and helpful comments.
文摘Surface plasmon polariton (SPP) is an attractive candidate to improve internal quantum efficiency (QE) of spontaneous emission (SE) from nano-structured silicon (Si) including nano-porous silicon (NP-Si) and silicon nanocrystal (Si-NC). Since the SPP resonant frequency of common metals, e.g., gold (Au), silver (Ag), copper (Cu), and aluminum (A1), is too high, the SPP resonance has to be engineered to match the luminescence from nano- structured Si. For this purpose, we have proposed and demonstrated three approaches including metal-rich Au(1-a)-SiO2(a) cermet SPP waveguide (WG), com- pound layer structure WG and metallic grating. In this paper, those approaches are reviewed and discussed. According to the calculated results, such three methods could effectively enhance SE rate from NP-Si or Si-NCs and show potential in developing high efficiency Si based light sources with electric pump.
文摘In this paper,we propose a photonic crystal fiber(PCF)polarization filter based on surface plasmon resonance(SPR)characteristics.Gold nanowire is used as the active plasmonic material.Light into silica core becomes coupled to gold nanowire stimulating SPR. It soplits light into two orthogonal(x-polarization and y-polarization)polarization in the second order of surface plasmon polarization.Numerical investigations of the proposed PCF filter is finite element method(FEM).By position,the performance of the propsed PCF filter is inspected rigorously.Filtering of any polarization can be obtained by properly placing the metal wires.The maximum cnfinement loss of x-polarization is 692.25dB/cm and y-polarization is 1.13dB/cm offers at resonance position 1.42μm.Such a confinement loss difference between two orthogonal polarizations makes PCF a talented candidate to filter devicees.Consequently,the recommended PCF structure is useful for polarization device.