Metallic nanoparticles(NPs)are a class of important materials with widespread applications due to their chemical stability and high photothermal conversion efficiency.It is essential to post-control the morphology and...Metallic nanoparticles(NPs)are a class of important materials with widespread applications due to their chemical stability and high photothermal conversion efficiency.It is essential to post-control the morphology and structure of metallic NPs for practical applications.Laser processing of metallic NPs has been widely investigated.Most of previous studies on the reshaping process have been related to the single metallic NPs,and no attempt has been made to separate the components in bimetallic NPs.Here,the stripping of Ag shell from Au@Ag NPs based on ultrafast laser excitation was investigated.The experimental work combined spectrum and microscopy analysis showed the structure transformation of Au@Ag NPs.Through the electric field simulation,the stripping of the Ag shell may arise from the electric field effect.展开更多
The effects of the nonlinear polarization in a partially stripped plasma on stimulated Brillouin scattering (SBS) process of a strong laser are discussed. A set of nonlineax mode coupling equations and the linear grow...The effects of the nonlinear polarization in a partially stripped plasma on stimulated Brillouin scattering (SBS) process of a strong laser are discussed. A set of nonlineax mode coupling equations and the linear growth rate of SBS instability is derived, respectively. When the intensity of an incident laser Io > 10^(17) W/cm^2, the third order susceptibility X(3) will reduce the above mentioned linear growth rate enormously. If taking the maximum value of the second order susceptibility X(2), the growth rate may be decreased observably when Io > 10_^(14)W/cm2. Furthermore, the nonlinear susceptibility can affect the nonlinear evolution of SBS much extensively.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51775303 and52075289)。
文摘Metallic nanoparticles(NPs)are a class of important materials with widespread applications due to their chemical stability and high photothermal conversion efficiency.It is essential to post-control the morphology and structure of metallic NPs for practical applications.Laser processing of metallic NPs has been widely investigated.Most of previous studies on the reshaping process have been related to the single metallic NPs,and no attempt has been made to separate the components in bimetallic NPs.Here,the stripping of Ag shell from Au@Ag NPs based on ultrafast laser excitation was investigated.The experimental work combined spectrum and microscopy analysis showed the structure transformation of Au@Ag NPs.Through the electric field simulation,the stripping of the Ag shell may arise from the electric field effect.
文摘The effects of the nonlinear polarization in a partially stripped plasma on stimulated Brillouin scattering (SBS) process of a strong laser are discussed. A set of nonlineax mode coupling equations and the linear growth rate of SBS instability is derived, respectively. When the intensity of an incident laser Io > 10^(17) W/cm^2, the third order susceptibility X(3) will reduce the above mentioned linear growth rate enormously. If taking the maximum value of the second order susceptibility X(2), the growth rate may be decreased observably when Io > 10_^(14)W/cm2. Furthermore, the nonlinear susceptibility can affect the nonlinear evolution of SBS much extensively.
