Reflection and frequency upshifting from electron density modulations produced by laser-plasma interaction; Towards the realization of attosecond, coherent X-ray source

Kando, Masaki; Fukuda, Yuji; Pirozhkov, A. S.; Ma, J.*; Chen, L.*; Esirkepov, T. Z.; Ogura, Koichi; Homma, Takayuki; Hayashi, Yukio; Bulanov, S. V.; Kotaki, Hideyuki; Sagisaka, Akito; Mori, Michiaki; Koga, J. K.; Kiriyama, Hiromitsu; Okada, Hajime; Faenov, A. Y.; Pikuz, T. A.*; Kawase, Keigo; Kameshima, Takashi; Kawachi, Tetsuya; Ragozin, E. N.*; Daido, Hiroyuki; Kimura, Toyoaki*; Kato, Yoshiaki* ; Tajima, Toshiki

We present a nobel method which can make it possible to generate attosecond, intense, coherent X-ray pulses. This method utilizes plasma electron modulation which is driven in an underdense plasma by an intense ultra-short laser pulse. The breaking wake wave works as a partially reflecting mirror (flying mirror) for incoming laser pulse. The reflected pulse is up-shifted in frequency and compressed in time by Doppler effect and inherits the coherence from the initial laser pulse. We show the proof-of-principle of the flying mirror concept and discuss the possibility of the future X-ray source.