Demonstration of light reflection from the relativistic mirror

相対論的鏡からの光の反射の実証

Pirozhkov, A. S.; Esirkepov, T. Z.; 神門 正城; 福田 祐仁; Ma, J.-L.; Chen, L. M.; 大東 出; 小倉 浩一; 本間 隆之; 林 由紀雄; 小瀧 秀行; 匂坂 明人; 森 道昭; Koga, J. K.; 大道 博行; Bulanov, S. V.; 木村 豊秋; 加藤 義章 ; 田島 俊樹

Pirozhkov, A. S.; Esirkepov, T. Z.; Kando, Masaki; Fukuda, Yuji; Ma, J.-L.; Chen, L. M.; Daito, Izuru; Ogura, Koichi; Homma, Takayuki; Hayashi, Yukio; Kotaki, Hideyuki; Sagisaka, Akito; Mori, Michiaki; Koga, J. K.; Daido, Hiroyuki; Bulanov, S. V.; Kimura, Toyoaki; Kato, Yoshiaki; Tajima, Toshiki

We present results of a proof-of-principle experiment and theoretical study of the frequency upshifting of the laser pulse reflected from the relativistic flying mirror. Experimentally, the breaking wake wave is created by a Ti:S laser pulse (2 TW, 76 fs) in helium plasma with the electron density of cm. The incidence angle of the second laser pulse on the flying mirror is 45, so the frequency upshifting factor is . The reflected radiation is observed in 24 shots using a grazing-incidence spectrograph. The wavelength changes from 7 to 14 nm, which corresponds to the frequency upshifting factors of 50-110 and the -factors of 4-6. The reflected signal contains at least photons/sr. The new source promises the generation of coherent ultrashort XUV and X-ray pulses with tunable wavelength and duration, with the possibility of focusing to record intensities.