@misc{oai:repo.qst.go.jp:00084865,
 author = {ITAKURA, Ryuji and Ryuji, Itakura},
 month = {Feb},
 note = {We investigate ultrafast dynamics of laser-plasma formation by measuring transient reflection from a PM formed by an intense laser pulse.  Transient reflectivity measurement enables us to visualize spatial dynamics of ablating surfaces.  The spallation in excited fused silica (FS) and organic polymers is clearly identified from a temporal oscillation lasting for longer than 500 ps with a period of several tens of picoseconds.   The surface expansion and densification in the outer region of an ablating hole are also suggested by the spatial dependence of the transient reflectivity measurement.  
  Using UV and VUV pulses, we measure the increase in reflectivity of the excited FS and water liquid sheet surfaces.  On the basis of the Drude model, it is suggested that the electron density increases to the level of 10^{22} cm^{-3}. 
The spectrum measurement of the transient reflection provides more exact time-dependent reflectivity including phase through the cross-correlation type frequency-resolve optical gating analysis., 4th Asian symposium on Intense Laser Science (ASILS) online seminar},
 title = {Transient-reflection spectroscopy of laser-plasma formation on solid and liquid surfaces},
 year = {2022}
}