@article{oai:repo.qst.go.jp:00081245,
 author = {Kohno, Nanase and Itakura, Ryuji and Tsubouchi, Masaaki and Ryuji, Itakura and Masaaki, Tsubouchi},
 issue = {23},
 journal = {Physical Review B},
 month = {Dec},
 note = {The relativistic Doppler reflection of terahertz (THz) light from a photoinduced moving plasma front in a silicon wafer irradiated by an optical pump light was investigated. The intensity and the phase shift spectra of the reflected THz light were investigated by THz time-domain spectroscopy with broadband electro-optic sampling in a thin GaP crystal. The frequency up-shift factor, which is a ratio of averaged frequencies from after to before Doppler reflection, was measured to be Gamma = 2.02 with a pump energy density of 3.3 μJ/mm2 at a wavelength of 800 nm. The frequency up-shift increased as optical pump energy density increased. The frequency up-shift was reproduced by evaluating the moving plasma front whose spatial carrier density distribution depended on the pump energy density.},
 pages = {235201-1--235201-9},
 title = {Relativistic Doppler reflection of terahertz light from a moving plasma front in an optically pumped Si wafer},
 volume = {102},
 year = {2020}
}