Fano resonances in the symmetry-broken gold-SiO2-gold(BGSG)nanotubes and the associated dimers have been investigated based on the finite element method.In the BGSG nanotube,the symmetry breaking induced the interacti...Fano resonances in the symmetry-broken gold-SiO2-gold(BGSG)nanotubes and the associated dimers have been investigated based on the finite element method.In the BGSG nanotube,the symmetry breaking induced the interactions of the inner gold core and outer gold nanoshell plasmons of all multipolar orders and hence the red-shifts of the plasmon resonance modes and the enhanced quadrupole mode peaks were observed.The interference of the quadrupole mode peak with the subradiant dipole mode caused a Fano-dip in the scattering spectrum.By increasing the core offset-value in the BGSG nanotube,the Fano dip with low energy showed a red-shift and became deeper.Unexpectedly the plasmon coupling between a GSG nanotube and a BGSG nanotube can lead to two strong Fano dips in the scattering spectra of the dimer.It was further noted that the thin side of the BGSG nanotube located at two sides of the dimer gap can lead to the strong near-field coupling between two BGSG nanotubes and hence a deeper and broader Fano dip.展开更多
The structure parameters of core-shell nanoparticles to optimize the photoacoustic(PA)efficiency were investigated.The gold nanotube was taken as the example of such nanoparticles.We studied PA effects through numeric...The structure parameters of core-shell nanoparticles to optimize the photoacoustic(PA)efficiency were investigated.The gold nanotube was taken as the example of such nanoparticles.We studied PA effects through numerical simulations based on the finite element method.Gold shells absorb the incident light and transfer heat into the surrounding polydimethylsiloxane(PDMS),where heat distributes exponentially.The more heat contains in the PDMS,the stronger PA signals will result.Therefore,PA signals grow with the thickness of the PDMS nonlinearly.The largest PA signal can be about 6 times of that from naked gold nanotubes.We also found that the optimal PA conversion can be obtained when the surface plasmon resonance matches with the wavelength of incident pulsed laser by adjusting structure parameters of gold nanotubes.This work may be helpful in the design of infrared PA contrast agents.展开更多
基金supported by the National Basic Research Program of China(Grant No.2012CB921504)the National Natural Science Foundation of China(Grant Nos.11174113,11204129 and 11274171)+1 种基金the Research Fund for the Doctoral Program of Higher Education of China(RFDP)(Grant Nos.20120091110001 and 20130091130004)Qing Lan Project of Jiangsu Province
文摘Fano resonances in the symmetry-broken gold-SiO2-gold(BGSG)nanotubes and the associated dimers have been investigated based on the finite element method.In the BGSG nanotube,the symmetry breaking induced the interactions of the inner gold core and outer gold nanoshell plasmons of all multipolar orders and hence the red-shifts of the plasmon resonance modes and the enhanced quadrupole mode peaks were observed.The interference of the quadrupole mode peak with the subradiant dipole mode caused a Fano-dip in the scattering spectrum.By increasing the core offset-value in the BGSG nanotube,the Fano dip with low energy showed a red-shift and became deeper.Unexpectedly the plasmon coupling between a GSG nanotube and a BGSG nanotube can lead to two strong Fano dips in the scattering spectra of the dimer.It was further noted that the thin side of the BGSG nanotube located at two sides of the dimer gap can lead to the strong near-field coupling between two BGSG nanotubes and hence a deeper and broader Fano dip.
基金supported by the Natural Science Foundation of Universities in Jiangsu Province(17KJB510032)。
文摘The structure parameters of core-shell nanoparticles to optimize the photoacoustic(PA)efficiency were investigated.The gold nanotube was taken as the example of such nanoparticles.We studied PA effects through numerical simulations based on the finite element method.Gold shells absorb the incident light and transfer heat into the surrounding polydimethylsiloxane(PDMS),where heat distributes exponentially.The more heat contains in the PDMS,the stronger PA signals will result.Therefore,PA signals grow with the thickness of the PDMS nonlinearly.The largest PA signal can be about 6 times of that from naked gold nanotubes.We also found that the optimal PA conversion can be obtained when the surface plasmon resonance matches with the wavelength of incident pulsed laser by adjusting structure parameters of gold nanotubes.This work may be helpful in the design of infrared PA contrast agents.
