## 1 Introduction  
The light-matter interaction process is one of the most fundamental physical process. Especially, with the development of laser technology, more and more new phenomena have been observed and investigated, such as multi-photon ionization (MPI) [1], above-threshold ionization (AT) [2], tunneling ionization (TI) [3] and high-harmonic generation (HHG) [4]. In molecular system, the ionization mechanism can be calculated by Keldysh theory [5, 6], where the Keldysh parameter \(\gamma\) is proposed to distinguish the MPI and TI under different laser intensities and wavelengths. When \(\gamma>>1\), the electron(s) will be ejected by absorbing several photons. However, in the case of \(\gamma<<1\), the potential barrier of the system will be distorted by the intense external electric field, and the electron(s) can escape the attraction from nuclei by tunneling the barrier or even over the barrier. After ionization, the dissociation would be observed, where some chemical bond(s) of the cation will be broken along the potential energy surface. It is well known that it takes hundreds of femtoseconds to break the molecular bond [7, 8, 9], thus the neutral molecule irradiated by femtosecond laser pulse will be firstly ionized, then the dissociation process occurs, which is called dissociative ionization (DI). During the low laser intensity (about \(10^{12}\)-\(10^{13}\) W/cm\({}^{2}\)), the ionization process depends strongly on the laser wavelengths [5]. After enough photons have been absorbed by molecules, which means the photon energies exceeds the threshold of ionization, the residual energy will be assigned to the kinetic energy and internal energy of fragments and electrons. When the laser intensity increases, the applied electric field strength is comparable to the internal coulomb attraction between nucleus and electron(s). In this case, the electron(s) can be easily stripped away and the charged molecular ions will further dissociate into fragments by the internal coulombic repulsive force, which is known as Coulomb explosion (CE) [10]. Differently from the resonant excitation with ultraviolet laser, the ionized molecule will be populated to numerous excited states due to the broad spectrum of the femtosecond pulses, and the dissociation dynamics can be observed along different chemical bonds simultaneously. Meanwhile, the coupling between excited states has influence on the dissociation dynamics [11]. Dibromodifluoromethane (CF\({}_{2}\)Br\({}_{2}\)) is widely used in fire retardant and refrigeration systems due to chemical inertness and nontoxicity, however, its photolysis in the stratosphere accelerates ozone layer destruction. For these reasons, the photodissociation of CF\({}_{2}\)Br\({}_{2}\) has been widely studied under the ultraviolet laser irradiation in the past decades. [PERSON] et al. [12] have studied the photochemistry of CF\({}_{2}\)Br\({}_{2}\) under 248 nm lasers field by the crossed laser-molecular beam technique [13]. Their results suggest that the molecular Br\({}_{2}\) elimination reaction, CF\({}_{2}\)Br\({}_{2}\)\(\rightarrow\) CF\({}_{2}\) + Br\({}_{2}\), cannot occur under their experiment condition. [PERSON] et al. [14] have studied the photodissociation dynamics of CF\({}_{2}\)Br\({}_{2}\) using 2D ion image technique. The difference of parameter \(\beta\) between channel (CF\({}_{2}\)Br + Br (\({}^{2}\)P\({}_{3/2}\))) and (CF\({}_{2}\)Br + Br (\({}^{2}\)P\({}_{1/2}\))) at 234 nm suggests that excited A\({}_{1}\) and B\({}_{1}\) states are strongly correlated by avoided curve crossing. However, the radical channel observed in 265 nm irradiation indicates the transition close to the curve crossing point is involved in the dissociation process. [PERSON] et al. [15] have studied the dissociation and ionization of CF\({}_{2}\)Br\({}_{2}\) excited under 266, 355 and 532 nm laser fields by time-of-flight mass spectrometry.