CONTROLLING ABOVE-THRESHOLD DISSOCIATION BRANCHING RATIOS OF HD⁺ WITH FEMTOSECOND LASER PULSE TRAIN

Abstract

Above-threshold dissociation (ATD) process of the molecular ions HD+ steered by a femtosecond laser pulse train (LPT) is investigated theoretically using the time-dependent quantum wave packet method. Energy-dependent distributions of ATD fragments are analyzed by using an asymptotic-flow expression in the momentum space. It is found that fragment kinetic energy spectra shift to low energy region with increasing pulse number of LPT. The photofragment branching ratio between the 1sσg and 2pσu dissociation channels is sensitive to the pulse number of LPT. The momentum distribution of the ATD fragments is discussed in detail.

Manifestation of external field effect in time-resolved photo-dissociation dynamics of LiF

“…One very interesting feature in Fig. 3 is that the position of the maximum (as expected, larger in amplitude) has a slight left shift when the laser intensity changes from 8×10 11 W/cm 2 to 8×10 12 W/cm 2 , and a more obvious dispersion of the wave packet takes place. Since the number of molecules pumped to the excited state is proportional to the laser intensity, it is easy to understand the increase of amplitude with intensity.…”

“…Indeed, Zewail and his coworkers obtained such relevant information for NaI by analyzing the features of FTS, and concluded that the potential well has a Morse-type shape. [3] In the interpretation of femtosecond pump-probe experiments, the theoretical treatment based on the time-dependent wave packet method has played an important role, especially in the studies of molecular photo-fragmentation, [5,6] multiphoton ionization, [7,8] and dissociation [9][10][11][12][13] of molecules under external fields. Using the results of wave packet calculations of dissociation dynamics with ab initio electronic energies and coupling elements, Regan et al [14] investigated the ultraviolet photo-dissociation of HCl in selected rovibrational states.…”

Time-dependent approach to the double-channel dissociation of the NaCs molecule induced by pulsed lasers

“…In addition, the TDWP method is especially suitable for the study of the real-time dynamics. It has given excellent results in the investigation of photo-ionization, [27] photodissociation, [28][29][30] photoassociation, [7] etc.…”