Femtosecond time-resolved zero kinetic energy photoelectron and photoionization spectroscopy studies of I2 wavepacket dynamics Original Research Article

We report the application of femtosecond zero kinetic energy (ZEKE) photoelectron spectroscopy and photoionization to the study of bound wavepacket motion in the electronic B state of iodine by a [1 + 2] multiphoton process. The experimental approach is described in detail. Comparisons of ZEKE photoelectron detection with ion detection are made. The pump wavelength was fixed at 580 nm whereas the probe wavelength was tuned from 350 to 300 nm. Wavepacket motion in the B state with the fundamental vibrational period of 340 fs was observed, as well as wavepacket dephasing and rephasing. Differences in the modulation depths and Fourier transform power spectra were observed. The phase shifts (time offset from Δt = 0) and modulation patterns varied as the location of the Condon point for the probe step changed upon tuning the probe wavelength. Higher-order wavepacket fractional revivals were observed in time-windowed Fourier transform power spectra.