Velocity map imaging of dissociative ionization of ICl in femtosecond laser field

The dissociative ionization of ICl after irradiation with a femtosecond laser pulse centered at 800 nm has been investigated. The speed distributions of produced I+ ions at a series of laser intensities have been measured and analyzed by velocity map imaging method. All of them can be fitted using four Gaussian functions. Four production channels are observed for I+ fragments, which originate from dissociation of A 2 Π i or B 2 Σ + states when the molecule is excited above the ionization threshold by multi-photon absorption. The images have shown obvious anisotropic character along the laser polarization.