Red Shift and Broadening of Backward Harmonic Radiation from Electron Oscillations Driven by Femtosecond Laser Pulse  

作　　者：田友伟 余玮 陆培祥 VinodK.SENECHA 除涵 邓德刚 李儒新 徐至展 

机构地区：[1]State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China [2]State Key Laboratory of Laser Technology,Huazhong University of Science and Technology,Wuhan 430074,China [3]Centre for Advanced Technology,Indore-452 013,India

出　　处：《Plasma Science and Technology》2006年第4期402-405,共4页等离子体科学和技术（英文版）

基　　金：supported by the National High-Tech ICF Committee of China (No.10335020/A0506);National Natural Science Foundation of China (Nos.10474081 and 10576035);Shanghai Natural Science Foundation (No.05ZR14159)

摘　　要：The characteristics of backward harmonic radiation due to electron oscillations driven by a linearly polarized fs laser pulse are analysed considering a single electron model. The spectral distributions of the electron＇s backward harmonic radiation are investigated in detail for different parameters of the driver laser pulse. Higher order harmonic radiations are possible for a sufficiently intense driving laser pulse. We have shown that for a realistic pulsed photon beam, the spectrum of the radiation is red shifted as well as broadened because of changes in the longitudinal velocity of the electrons during the laser pulse. These effects are more pronounced at higher laser intensities giving rise to higher order harmonics that eventually leads to a continuous spectrum. Numerical simulations have further shown that by increasing the laser pulse width the broadening of the high harmonic radiations can be controlled.The characteristics of backward harmonic radiation due to electron oscillations driven by a linearly polarized fs laser pulse are analysed considering a single electron model. The spectral distributions of the electron＇s backward harmonic radiation are investigated in detail for different parameters of the driver laser pulse. Higher order harmonic radiations are possible for a sufficiently intense driving laser pulse. We have shown that for a realistic pulsed photon beam, the spectrum of the radiation is red shifted as well as broadened because of changes in the longitudinal velocity of the electrons during the laser pulse. These effects are more pronounced at higher laser intensities giving rise to higher order harmonics that eventually leads to a continuous spectrum. Numerical simulations have further shown that by increasing the laser pulse width the broadening of the high harmonic radiations can be controlled.

关 键 词：harmonic emission broaden red shift femtosecond laser 

分 类 号：TN241[电子电信—物理电子学]