Wavelength dependence of photoelectron momentum distributions in a spatially inhomogeneous field

Abstract

The effect of the spatial inhomogeneity on the photoelectron momentum distributions (PMDs) is recently identified [Chen et al., Phys. Rev. A 104, 043107 (2021)]. As an important parameter of the laser field, the wavelength cannot be ignored. We theoretically investigate the wavelength dependence of the PMDs in a spatially inhomogeneous field. The results show that the PMDs gradually move to the negative direction with the increase of the laser wavelength compared with the case of the spatially homogeneous field. However, a critical value of the wavelength appears, where the PMDs are just separated. Then, the PMDs can be clearly separated into two regions and the rescattering energy of the electron is tremendously enhanced. We illustrate that the holographic interference structure can be isolated in the relative high-energy region and the holographic interference structure for the shorter wavelength is more obvious. A prominent high-energy peak appears in the critical wavelength and the high-energy peak is sensitive to the initial transverse momentum of the rescattering electrons after tunneling. Moreover, we also demonstrate that the critical wavelength will change with the inhomogeneity parameters.