High order harmonics from relativistic electron spikes

相対論的電子スパイクからの高次高調波発生

Pirozhkov, A. S.; 神門 正城; Esirkepov, T. Z.; Gallegos, P.*; Ahmed, H.*; Ragozin, E. N.*; Faenov, A. Ya.*; Pikuz, T. A.*; 河内 哲哉; 匂坂 明人; Koga, J. K.; Coury, M.*; Green, J.*; Foster, P.*; Brenner, C.*; Dromey, B.*; Symes, D. R.*; 森 道昭; 川瀬 啓悟*; 亀島 敬*; 福田 祐仁; Chen, L.-M.*; 大東 出*; 小倉 浩一; 林 由紀雄; 小瀧 秀行; 桐山 博光; 岡田 大; 西森 信行; 今園 孝志; 近藤 公伯; 木村 豊秋*; 田島 俊樹*; 大道 博行; Rajeev, P.*; McKenna, P.*; Borghesi, M.*; Neely, D.*; 加藤 義章* ; Bulanov, S. V.

Pirozhkov, A. S.; Kando, Masaki; Esirkepov, T. Z.; Gallegos, P.*; Ahmed, H.*; Ragozin, E. N.*; Faenov, A. Ya.*; Pikuz, T. A.*; Kawachi, Tetsuya; Sagisaka, Akito; Koga, J. K.; Coury, M.*; Green, J.*; Foster, P.*; Brenner, C.*; Dromey, B.*; Symes, D. R.*; Mori, Michiaki; Kawase, Keigo*; Kameshima, Takashi*; Fukuda, Yuji; Chen, L.-M.*; Daito, Izuru*; Ogura, Koichi; Hayashi, Yukio; Kotaki, Hideyuki; Kiriyama, Hiromitsu; Okada, Hajime; Nishimori, Nobuyuki; Imazono, Takashi; Kondo, Kiminori; Kimura, Toyoaki*; Tajima, Toshiki*; Daido, Hiroyuki; Rajeev, P.*; McKenna, P.*; Borghesi, M.*; Neely, D.*; Kato, Yoshiaki*; Bulanov, S. V.

We present a detailed description of our discovery of a new regime of high-order harmonic generation, including experimental data, simulations, and description of new harmonic generation mechanism. The harmonics are generated by multi-terawatt relativistic-irradiance ( 10 W/cm) femtosecond ( 30-50 fs) lasers focused to gas jet targets. According to our model, the harmonics are produced by sharp, structurally stable, oscillating electron spikes at the joint of boundaries of wake and bow waves excited by the laser pulse.