飞秒激光作用下不同热处理状态Tb0.27Dy0.73Fe2薄膜的瞬时反射率

飞秒激光作用下不同热处理状态Tb_0.27Dy_0.73Fe₂薄膜的瞬时反射率

摘要: 为了提高Tb0.27Dy0.73Fe2薄膜材料的性能,运用飞秒激光泵浦-探测技术研究了泵浦光功率和550 ℃退火对Tb0.27Dy0.73Fe2薄膜瞬时反射率的影响.结果表明:飞秒激光作用下未退火薄膜的瞬时反射率ΔR/R曲线分四个阶段,在最初的200.1 fs内其反射率从之前的稳定值上升到极大值,随后经过200.1 fs,反射率到达极小值后达到稳定状态;而退火后的Tb0.27Dy0.73Fe2薄膜ΔR/R曲线只有三个阶段,在零点时刻就开始下降,并在200.1 fs之后达到稳定状态;随着泵浦光功率的增大,薄膜ΔR/R曲线的极值呈线性增加.

Abstract: The effects of pump power and annealed at 550 ℃ on the instantaneous reflectivity of Tb0.27Dy0.73Fe2 films was studied by femtosecond laser pump-probe technology for improving the characteristics of the materials.The results show that the instantaneous reflectivity ΔR/R curves of unannealed film had four stages,first the reflectivity arrived at the maximum after 200.1 fs excited by femtosecond laser,and then the system was in equilibrium after 200.1 fs.ΔR/R curves of annealed film started to decrease at zero,and then arrived equilibrium after 200.1 fs.With the increasing of pump power the change extent of ΔR/R curve was linear.