A nonperturbative quantum electrodynamic approach to the theory of laser induced high harmonic generation  

作　　者：Chao Yu Jingtao Zhang Zhi-Wei Sun Zhenrong Sun Dong-Sheng Guo 

机构地区：[1]State Key Laboratory of Precision Spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, China [2]State Key Laboratory of High-field Laser Physics, Shanghai Institute of Optical and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China [3]Key Laboratory of Microgravity, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China [4]School of Physics, Peking University, Beijing 100871, China

出　　处：《Frontiers of physics》2015年第4期45-50,共6页物理学前沿（英文版）

摘　　要：Using nonperturbative quantum electrodynamics, we develop a scattering theory for high harmonic generation （HHG）. A transition rate formula for HHG is obtained. Applying this formula, we cal- culate the spectra of high harmonics generated from different noble gases shined by strong laser light. We study the cutoff property of the spectra. The data show that the cutoff orders of high harmonics are greater than that predicted by the ＂3.17＂ cutoff law. As a numerical experiment, the data obtained from our repeated calculations support the newly derived theoretical expression of the cutoff law. The cutoff energy of high harmonics described by the new cutoff law, in terms of the ponderomotive energy Up and the ionization potential energy Ip, is 3.34Up 1.83Ip. The higher cutoff orders predicted by this theory are due to the absorption of the extra photons, which participate only the photon-mode up-conversion and do nothing in the photoionization process.Using nonperturbative quantum electrodynamics, we develop a scattering theory for high harmonic generation （HHG）. A transition rate formula for HHG is obtained. Applying this formula, we cal- culate the spectra of high harmonics generated from different noble gases shined by strong laser light. We study the cutoff property of the spectra. The data show that the cutoff orders of high harmonics are greater than that predicted by the ＂3.17＂ cutoff law. As a numerical experiment, the data obtained from our repeated calculations support the newly derived theoretical expression of the cutoff law. The cutoff energy of high harmonics described by the new cutoff law, in terms of the ponderomotive energy Up and the ionization potential energy Ip, is 3.34Up 1.83Ip. The higher cutoff orders predicted by this theory are due to the absorption of the extra photons, which participate only the photon-mode up-conversion and do nothing in the photoionization process.

关 键 词：high harmonic generation （HHG） cutoff law strong laser physics nonperturbative quantum electrodynamics transition rate formula 

分 类 号：O413.2[理学—理论物理] TN241[理学—物理]