【摘要】 对基于表面等离子体激元共振(SPR)的飞秒抽运探测技术进行了系统地数字分析.计算结果表明,利用SPR技术可将飞秒抽运探测信号强度ΔR/R提高2—3个数量级,其提高的比例依赖于金属膜的厚度和探测光的入射角,其中R和ΔR分别为探测光反射率的总量和变化量.特别地,对于金属-吸收介质体系,金属膜的介电常数变化对ΔR的影响仅为吸收介质影响的2%,所以ΔR/R主要反应吸收介质中的动力学过程,因此该技术对研究表面和界面的超快动力学过程具有重要的意义.更多还原

【Abstract】 Femtosecond pump-probe technique assisted by surface plasmon resonance (SPR) is investigated numerically in this paper. Our calculations show that the signal ratio ΔR/R is increased by 2—3 orders of magnitude higher than the standard pump-probe technique, where ΔR and R are the intensity change and total intensity of the probe beam, respectively. It should also be pointed out that ΔR/R is sensitive to the incident angle of the pump beam and the thickness of the metal film. In particular for the metal-absorbing material system, ΔR induced by the hot electrons in the metal is only 2 percent of that induced by excited absorbing material, so ΔR/R is mainly related to the dynamics of the absorbing material. This technique will be interesting in investigating the ultrafast surface dynamics of thin films.更多还原