Pondermotive Shift of Photoelectron Spectra in Intense Laser Field
BAI Li-Hua1,2, ZHANG Jing-Tao1, WANG Yi1, XU Zhi-Zhan1
1State Key Laboratory for High Field Laser Physics, Shanghai Institute of Optics and Fine mechanics, Chinese Academy of Sciences, Shanghai 201800
2Graduate School of Chinese Academy of Sciences, Beijing 100049
Pondermotive Shift of Photoelectron Spectra in Intense Laser Field
BAI Li-Hua1,2;ZHANG Jing-Tao1;WANG Yi1;XU Zhi-Zhan1
1State Key Laboratory for High Field Laser Physics, Shanghai Institute of Optics and Fine mechanics, Chinese Academy of Sciences, Shanghai 201800
2Graduate School of Chinese Academy of Sciences, Beijing 100049
Abstract： In a recent experimental work on the excess photon detachment (EPD) of H- ions [Phys. Rev. Lett. 87(2001)243001], it has been found that the ponderomotive shift of each EPD peak increases with the order of the EPD channel. By using a nonperturbative quantum scattering theory, we obtain the kinetic energy spectra for the differential detachment rate along the laser polarization for several laser intensities. It is demonstrated that higher order EPD peaks are produced mainly at relatively higher laser intensities. By calculating the overall EPD spectra with varying laser intensities, it is found that the ponderomotive shift of each EPD peak increases with the order of the EPD channel. Our calculations are in good agreement with the experimental observation. It is found that different EPD channels occur mainly when the laser field reaches some values, thus the intensity distribution of the laser field is responsible for the varying ponderomotive shifts.
2006, Vol. 23 
