Figure 1

Typical transient profile obtained by monitoring the $o$-dichlorobenzene parent-ion mass (147 amu) signal. The open circles are experimental data, and the solid line is the best fit to an exponential decay convoluted with a Gaussian response function of 260 fs. The inset (solid circles) is the cross-correlation curve of pump and probe pulses.Reuse & Permissions

Figure 2

Time-resolved photoelectron images, photoelectron-angular distributions, in a (1 + 4′) resonance-enhanced multiphoton ionization via the $S_1$. The pump-laser wavelength was fixed to a $S_1\leftarrow S_0$ transition (267 nm), and the probe-laser wavelength was 800 nm. The linear polarizations of the pump and probe lasers are aligned vertical in the plane of the figure. (a) BASEX transforms of the time-resolved photoelectron images corresponding to the slices through the 3D photoelectron velocity distributions at specified time delays. (b) Polar plots of the photoelectron-angular distributions corresponding to the second band associated with ionization from the $S_1$ to the $D_1$ at specified time delays. Solid lines are theoretical fits.Reuse & Permissions

Figure 3

Photoelectron kinetic energy distributions extracted from the images of Fig. 2. The arrows indicate the photoelectron energy (1.77 and 1.21 eV) expected for ionization to the zero vibrational level of the cation indicated by $D_0$ and $D_1$, by four-photon absorption of the probe pulse.Reuse & Permissions

Figure 4

A schematic illustration of the possible ionization pathways. Here, 1st (Apply superscript formatting to st.) $2^{\mathrm{nd}}$, and 3rd (Apply superscript formatting to rd.) correspond to the first, second, and third bands.Reuse & Permissions

Figure 5

Anisotropy parameters of the first, second, and third bands as a function of pump-probe time delay.Reuse & Permissions

Figure 6

Time dependence of photoelectron angular distribution obtained for PEI via $S_1$. Pump-probe delay was scanned from 280 to 310 ps with a 1-ps interval. The first full revival of the rotational wave packet is at 296 ps.Reuse & Permissions