提高高次谐波效率一直是强场物理研究中的一个重要课题,对此人们采取了很多方法,如采用双色场、实现相位匹配、附加一个强电场或强磁场等.本文在研究双色场高次谐波的过程中,发现原子的能级结构对于高次谐波的产生效率有极大的影响,据此提出利用附加共振高频场来大幅度提高高次谐波的产生效率.

How to enhance the efficiency of high order harmonic generation is an important topic in high field physics. Many ways including two color laser field, phase matched in a gas filled hollow fiber and adding a magnetic field, etc. are adopted. In the investigation of two color field high order harmonic generation, it is found that the atomic energy level structure greatly affects the high order harmonic generation. For a certain level structure, a specially chosen high frequency additional driving field can greatly enhance the efficiency of high order harmonic generation.