超短脉冲强激光场中氙的高次谐波

High-order Harmonics in Xe Using Intense Ultra-short Laser Pulses

在静态气室中,利用线偏振的掺钛蓝宝石(Ti:sapphire)超短脉冲激光(中心波长795nm,脉宽105fs,重复频率10Hz,单脉冲能量50mJ),获得氙气中5～17次(40～160nm)谐波的软X射线激光辐射。实验中着重观察了高次谐波谱线强度随激光强度的变化规律,由于激光强度已经接近甚至超过饱和,高次谐波谱相对强度随入射激光强度增加而增长到一定程度后开始下降,同时观察到介质的离子谱,证实了高次谐波谱的产生与离子辐射之间的转换关系。

In static gas target, the 5th-17th (40-160 nm) high harmonic generation soft X-ray laser radiation has been obtained using linearly-polarized Ti: sapphire ultra-short laser pulses (central wavelength is 795 nm, pulse duration is 105 fs, repetition rate is 10 HZ, and one pulse energy is 50 mJ). The change of high harmonic spectra intensities vs input laser power is especially observed. Because the incident laser intensities verge on or even exceed the saturation intensities in this experiment, the high-order harmonic intensities begin to decrease after increase with incident laser power increase, and the ion spectra of gas have been observed in the same time, which verify the conversion relationship between the high harmonic generation and ion spectra radiation.