Photoelectron imaging of resonance-enhanced multiphoton ionization and above-threshold ionization of ammonia molecules in a strong 800-nm laser pulse
Song Le-Le1, 2, 3, Sun Ya-Nan1, 3, Wang Yan-Hui4, Wang Xiao-Chun1, 3, He Lan-Hai1, 3, Luo Si-Zuo1, 3, Hu Wen-Hui1, 3, Tong Qiu-Nan1, 3, Ding Da-Jun1, 3, Liu Fu-Chun1, 3, †
       

NH3 molecular photoelectron images at 800-nm laser wavelength. (a)–(e) Low laser intensity region. The laser intensities are 1.6×1013 W/cm2, 1.9×1013 W/cm2, 2.2×1013 W/cm2, 2.5×1013 W/cm2, and 2.7×1013 W/cm2, respectively. (f)–(j) High laser intensity region. The laser intensities are 3.1×1013 W/cm2, 3.8×1013 W/cm2, 4.4×1013 W/cm2, 5.0×1013 W/cm2, and 5.7×1013 W/cm2, respectively. Horizontal and vertical coordinates are x-pixel and y-pixel from CCD, and laser polarization direction is indicated by arrow.