[21p-S622-1~20] 3.6 Ultrashort-pulse and high-intensity lasers

△ [21p-S622-3] Observation of Surface Plasmon Polaritons on Si excited with an Intense Femtosecond Laser Pulse

〇(M1)Masato Hagiya¹, Godai Miyaji¹ (1.Tokyo Univ. of A & T)

Keywords:surface plasmon polaritons,femtosecond laser,silicon

We report the first demonstration, using the reflectivity measurement, on excitation of surface plasmon polaritons (SPPs) on Si with an intense femtosecond (fs) laser pulse with the wavelength of 800 nm. With the p-polarized fs laser pulse at high fluence above the single-shot ablation threshold of Si, the reflectivity changes of a Si grating have been observed as a function of the incident angle. To understand the characteristic properties of the SPPs excited, we measured the reflectivity of the Si grating with the fs laser pulse at different fluences. The experimental results obtained show that this technique can sensitively observe the density of electrons excited on Si and the damping of the SPPs.