Development of the single shot soft X-ray interferometer for observation of the nanometer-scaled surface dynamics

Hasegawa, Noboru; Kawachi, Tetsuya; Nishikino, Masaharu; Ochi, Yoshihiro; Terakawa, Kota*; Takei, Ryota*; Minami, Yasuo*; Baba, Motoyoshi*; Suemoto, Toru; Yamagiwa, Mitsuru

We developed the soft X-ray laser interferometer synchronized with Ti:Sapphire laser pulse for the measurement of the nanometer-scaled surface dynamics. The soft X-ray laser is suitable for probing the initial process of the surface morphological changes, because it has the suitable wavelength (= 13.9 nm), short duration (= 7 ps) and large photon numbers. By using this system, we succeed to obtain the temporal evolution of ablation front erupting from the laser induced Pt film. From this result, it was revealed that the expansion speed of the ablation front decreased continually from the center (= 2200 m/s) to the edge (= 420 m/s) of the ablation area in the initial stage of the ablation process.